Browse Topic: Connecting rods

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Automation Title for Group Code D22PC-Auto-1752670240025 (Current)7/16/2025
Automation Abstract for Group Code D22
Airlines Electronic Engineering Committee
USUALLY UNOBSERVED REFINEMENTS OF AUTOMOBILE CONSTRUCTION0800031/1/2024
ELLSWORTH, JOHN MAGEE, FAY, THOMAS J.
Lubricating Oil, Aircraft Piston Engine (Ashless Dispersant)J1899_202010 (Current)10/28/2020
This SAE Standard establishes the requirements for lubricating oils containing ashless dispersant additives to be used in four-stroke cycle, reciprocating piston aircraft engines. This document covers the same lubricating oil requirements as the former military specification MIL-L-22851. Users should consult their airframe or engine manufacturers manuals for the latest listing of acceptable lubricants.
E-38 Aviation Piston Engine Fuels and Lubricants
A New Cavitation Algorithm to Support the Interpretation of LIF Measurements of Piston Rings2020-01-10914/14/2020
Laser induced fluorescence (LIF) is used to investigate oil transport mechanisms under real engine conditions. The engine oil is mixed with a dye that can be induced by a laser. The emitted light intensity from the dye correlates with the residual oil at the sensor position and the resulting oil film thicknesses can be precisely determined for each crank angle. However, the general expectation is not always achieved, e.g. an exact representation of piston ring barrel shapes. In order to investigate the responsible lubrication effects of this behavior, a new cavitation algorithm for the Reynolds equation has been developed. The solution retains the mass conservation and does not use any switch function in its mathematical approach. In contrast to common approaches, no vapor-liquid ratio is used, but one or several bigger bubbles are approximated, as have been observed in other experiments already. As a result, not only the known boundary conditions for the Reynolds equation become unnecessary, but the solution also gives a clearer idea as to the shape of the cavitation bubble. The combination of simulated oil film thicknesses, the resulting cavitation bubbles and the fixed field of view from the LIF sensor allows a reproduction of the measurement signal. The comparison of measurement and simulation exhibits a high correlation, and thus enables a deeper knowledge and understanding of the real conditions inside a combustion engine. On the other hand, it can be seen that effects such as a decrease in the LIF signal in the cavitation area is much lower than would be expected according to the literature.
Ruch, Fabian H., Wachtmeister, Georg
Further Experiments on the Effect of Bulk In-Cylinder Temperature in the Pressurized Motoring Setup Using Argon Mixtures2020-01-10634/14/2020
Mechanical friction and heat transfer in internal combustion engines have long been studied through both experimental and numerical simulation. This publication presents a continuation study on a Pressurized Motoring setup, which was presented in SAE paper 2018-01-0121 and found to offer robust measurements at relatively low investment and running cost. Apart from the limitation that the peak in-cylinder pressure occurs around 1 DegCA BTDC, the pressurized motoring method is often criticized on the fact that the gas temperatures in motoring are much lower than that in fired engines, hence might reflect in a different FMEP measurement. In the work presented in SAE paper 2019-01-0930, Argon was used as the pressurization gas due to its high ratio of specific heats. This allowed to achieve higher peak in-cylinder temperatures which close further the gap between fired and motored mechanical friction tests. In 2019-24-0141, Argon was mixed in different proportions with Air to synthesize gases with different ratios of specific heats in the aim of observing any abrupt transitions in the FMEP with different peak in-cylinder temperatures. In this publication, a higher loading test matrix to that published in 2019-24-0141 is presented, with an engine speed ranging from 1400 rpm to 3000 rpm and ratios of specific heats varying from that of Air (γ = 1.4) to that of Argon (γ = 1.67). The peak in-cylinder pressure was kept at a constant 103 bar. Results obtained in this work strengthen further the observations made in 2019-24-0141; where the measured FMEP is found to be insensitive to the different peak in-cylinder temperatures. In this study, a fast-response thermocouple of the eroding type was also fitted in the combustion chamber and gas-wall interface temperature histories were recorded. The transient heat flux was also computed through a spectral analysis and reported in this publication.
Caruana, Carl, Farrugia, Mario, Sammut, Gilbert, Pipitone, Emiliano
Functionality Analysis of Thermoplastic Composite Material to Design Engine Components2020-01-07744/14/2020
Developing of innovative technologies and materials to meet the requirements of environmental legislation on vehicle emissions has paramount importance for researchers and industries. Therefore, improvement of engine efficiency and fuel saving of modern internal combustion engines (ICEs) is one of the key factors, together with the weight reduction. Thermoplastic composite materials might be one of the alternative materials to be employed to produce engine components to achieve these goals as their properties can be engineered to meet application requirements. Unidirectional carbon fiber reinforced PolyEtherImide (CF/PEI) thermoplastic composite is used to design engine connecting rod and wrist pin, applying commercial engine data and geometries. The current study is focused on some elements of the crank mechanism as the weight reduction of these elements affects not only the curb weight of the engine but the overall structure. As a matter of fact, by reducing the reciprocating mass, alternate forces will be reduced and hence the size of the structural elements. Also, other elements of the engine can be designed for lightweighting, but the crank mechanism elements maximize the effects, by reducing both loads and weight. Finite element analysis (FEM) has been conducted for proper stress analysis and accordingly examine the design and parts functionalities. FEM analysis is performed using Altair HyperMesh for mesh optimization to conduct stress analysis of standard engine components made of steel and to redesign the parts using thermoplastic material to sustain the loads and stresses. Then the design modification has been considered to reduce loads and weight without parts performance interruption under service.
Razavykia, Abbas, Delprete, Cristiana, Rosso, Carlo, Baldissera, Paolo
The Isochoric Engine2020-01-07964/14/2020
For the gasoline engine, the isochoric process is the ideal limit of the ideal processes. During the project, a combustion engine with real isochoric boundary conditions is built. A “resting time” of the piston for several degrees crank angle in the top dead center (TDC) can be realized with a special crank drive. This crank drive consists of two crankshafts with different strokes, which are combined. The two crankshafts rotate with a ratio of two to one in opposite directions. The total stroke corresponds to the amount of the first crankshaft, so it is possible to investigate different strokes of the second crankshaft in the same crankcase. Different “resting times” can be achieved by different strokes of the second crankshaft. A specific combination of both crankshafts make a stroke possible which corresponds to that of a conventional combustion engine. In addition to the standard cylinder pressure sensor, a quick surface temperature probe is also used as supplementary measurement technology. The influence of isochoric combustion is studied with constant air mass and constant lambda at three different strokes of the small crankshaft.
Burger, Benjamin, Bargende, Michael
Connecting Rod Durability and Big-End Bore Distortion Study2020-01-01844/14/2020
The prediction of the connecting rod behaviour is one of the most important aspects of the engine design to estimate the engine life and its NVH behaviour. Connecting rod is usually simulated as a stand-alone component replacing the connected members with boundary conditions. These kinds of simulation usually underestimate the life of the connecting rod and overestimate the crankpin distortion. This unreal behaviour of simulation can result in over design of the crankshaft and wrong crankpin bearing selection, which can result in a noisy engine. The current Finite Element Analysis (FEA) is modelled by considering crankshaft, bearings, 3D bolts and crankcase substructure along with the connecting rod to predict the fatigue life and bearing distortion. A multi-body dynamics (MBD) simulation of the Cranktrain has been carried out to predict the forces and accelerations on the connecting rod by including the combustion force with a constant crankshaft speed for different conditions. The extracted loads from MBD simulation at different conditions are imported into FEA model, to predict stresses at maximum combustion and maximum inertia stages. Journal bearing crushing and bolt preload are the initial steps to the simulation. The predicted stresses from FEA has been considered as input for the fatigue life prediction following the engine endurance cycle including the residual stresses. The big end distortion has been Fourier transformed to extract the bounds which give insight into clearance limit in the operating conditions. Fatigue life prediction and the big end distortion from the regular stand-alone connecting rod model and FEA assembly method has been compared and discussed. The wear pattern on the big end bearing in testing emulated the contact pressure pattern on the assembly method, which emphasises the importance of modelling the connecting rod durability as an assembly model.
Thekke Kolayath, Nabeel, T, Sreenivasulu, Giles, Rod
Internal Combustion Engines - Piston VocabularyJ2612_202002 (Current)2/18/2020
This SAE standard defines the most commonly used terms for pistons. These terms designate either types of pistons or certain characteristics and phenomena of pistons.
Piston and Ring Standards Committee
Friction Reduction of an All-aluminum Cylinder for Motorcycles by a Mirror Finished Bore with Dimples2019-32-05301/24/2020
In recent years, the demand for fuel economy of small engines has been increasing for further improvement of product competitiveness. As a solution for this issue, a lot of developments on reduction of friction losses of engine components have been actively performed by engine manufacturers, especially the friction loss between the cylinder bores and pistons or piston rings is main issue to solve because these frictions highly contribute to the fuel economy for the small engines. In this study, focusing on the effect of the texture of the all-aluminum cylinder bore on friction loss, we verified the friction loss of all-aluminum cylinders having several kinds of surface textures by a floating liner method. For the evaluation, we prepared cylinders which have the texture of the following three types, 1) plateau type (having conventional cross-hatches), 2) mirror finished type (having no cross-hatches and no irregular surface characteristics), 3) dimple type (most of part is mirror finished but small dimples are given at a limited part). As a result of the evaluation, it was confirmed that FMEP of mirror type was 14.1% lower and dimple type (optimized for low friction) was 19.5% lower than plateau type. In addition, when comparing FMEP for each crank angle, it was revealed that mirror type was effective evenly in all strokes of intake, compression, expansion, and exhaust, and the dimple showed a large effect particularly on the expansion stroke.
Murase, Yuta, Kumagai, Hideya
Development of a Novel Hybrid-Piston for Application in High Performance Two-Stroke Engines2019-32-05081/24/2020
The current development trends for high performance two-stroke engines have been identified in raising combustion pressures and therefore higher cylinder temperatures [1] [2]. Thus, the requirements on piston assembly are increased in such a way that pistons based on aluminium-silicon alloys – as most commonly used in high performance two-stroke engines - reach their application limit. A suitable solution has been shown by research work such as that conducted by Mahle König, by using a piston consisting of different materials. With this approach, the higher stressed piston crown consists of steel, while the lower stressed piston skirt is made out from aluminium. Previous basic examinations showed the high potential of the hybrid piston concept in terms of pressure and temperature increase, while also showing the need for a temperature-stable and pressure-tight joint between crown and skirt. This paper will focus on the development of two novel hybrid-piston concepts, where the piston crown and the piston skirt are connected in different ways. The first hybrid concept presented uses the piston pin in order to realize a plugconnection between piston crown and piston skirt (a conjunction hereafter known as plug-connection). A second approach is a material joint between piston crown and piston skirt, with the result that the two parts are integrally joined to one another (a conjunction hereafter known as multimaterial joint). During the predevelopment phase the design and dimensioning of the hybrid concepts were carried out with reference to mechanical and thermal operation loads, as well as joining aspects. A specific joining concept using a bimetal transition joint was created, along with the development of a special adapted laser beam welding procedure. The multi-material joint properties were further verified by FEM simulations as well as by mechanical and thermal tests. Finally, hybrid-piston prototypes were produced in time for first bench tests. In this paper the design concept of the hybrid piston and the joining technology will be presented, along with the results of FEM simulations and material testing.
Bechter, Christian, Jahn, Axel, Zimmermann, Frieder, Stamm, Uwe, Herb, Thomas
Dynamic oil pressure in connecting rod bearings and their influence on innovative cranktrain technologies2019-01-233312/19/2019
In order to lower friction losses and hence ensure low fuel consumption of internal combustion engines, borderline design of hydrodynamic cranktrain bearings is often unavoidable. To realize this without the risk of failures, detailed modelling of hydrodynamic effects is gaining more and more relevance. In this publication, an approach using flow simulation to couple hydrodynamic bearings with each other, will be introduced. This allows the state variables of the fluid in the supply bore of the crankshaft to be calculated transiently. One important aspect of this concerns the solubility of gas in oil. This paper demonstrates that the gas fractions in the supply bore of the crankshaft influence the pressures at the hydrodynamic bearings. Additionally, simulation results will be shown and also validated with measurement data. Beside the application for conventional cranktrains, the developed methodology can also be applied to investigate lubrication systems, which include innovative technologies such as hydraulic, length adjustable connecting rods employed for variable compression ratio (VCR connecting rod).
Pendovski, Denis, Pischinger, Stefan
A study of Measurement for Oil Film at the Bearing of the Small End of Diesel Engine Connecting Rod2019-01-233212/19/2019
Downsizing and slowing down of engine speed reduce mechanical losses and improve fuel economy. However, they exacerbate lubrication condition. The oil film thickness of the bearing of the small end of the connecting rod, which was one of the sliding surfaces with the severest lubrication condition in a diesel engine, was measured in this study to clarify the lubrication condition. Optical fibers were embedded in the bearing, and oil film was measured by means of the laser induced fluorescence method. It was found that oil film thickness was affected combustion gas pressure and distortion of the piston pin.
Suzuki, Shotaro, Yamada, Shota, Ito, Akemi
Study of the Effects of Oil Supply and Piston Skirt Profile on Lubrication Performance in Power Cylinder Systems2019-01-236412/19/2019
In internal combustion engines, the majority of the friction loss associated with the piston takes place on the thrust side in early expansion stroke. Research has shown that the Friction Mean Effective Pressure (FMEP) of the engine can be reduced if proper modifications to the piston skirt, which is traditionally barrel-shaped, are made. In this research, an existing model was applied for the first time to study the effects of different oil supply strategies for the piston assembly. The model is capable of tracking lubricating oil with the consideration of oil film separation from full film to partial film. It is then used to analyze how the optimized piston skirt profile investigated in a previous study reduces friction. It was found that the profile is able to maintain a larger amount of lubricant between the lower part of the piston skirt and the cylinder liner during compression stroke, thereby generating more hydrodynamic pressure, instead of asperity contact pressure, to balance the lateral force from piston pin.
Meng, Zhen, Ahling, Sebastian, Tian, Tian
Research of the High Altitude Control Strategy of the Piston Aero-engine Using Two-stage Turbocharger Coupled with single Supercharging System2019-01-221112/19/2019
Aiming at the high altitude operation problems for piston-type aero-engines and to improve the practical ceiling and high altitude dynamic performance, this thesis analyzes a controllable three-stage composite supercharging system, using a two-stage turbocharger coupled supercharger method. The GT-Power simulation model of a four-cylinder boxer engine was established, and the control strategy of variable flight height was obtained. The simulation research of engine performance from 0 to 20,000 meters above sea level has been carried out, which shows that the engine power is at the same level as the plain condition, and it could still maintain 85.28 percent of power even at the height of 20,000 meters, which meets the flight requirements of the aircraft.
Yao, Ye, Shi, Lei, Zhang, Zhe, Xiao, Maoyu, Liu, Mingwei, Tan, Jianwei
Effect of Eccentric Imbalance of Various Crank Train Components on Vibrations in Single Cylinder Diesel Engines2019-28-241711/21/2019
Diesel engine is the main source of power for many agricultural applications such as water pump sets, compressors and tractors. At the same time it is also the main source of vibrations. Mechanical vibrations have instantaneous and long term effects on human body. Kinds of effects depend upon duration of exposure and frequency of vibrations. The increasing demands of improved comfort levels of operators are putting pressures on tractor manufacturers on reducing the vibration levels which thereby resulting in improving diesel engine vibrations. Vibration is the movement or mechanical oscillations about an equilibrium position of a machine or component. A Vibration analysis is about the art of looking for changes in the vibration pattern and then relating those changes. Vibration always occurs when there is unbalanced body in reciprocating or rotary motion. In an internal combustion engine there are many parts in reciprocating and rotary motion such as pistons, connecting rod, crankshaft, flywheel etc. This paper explains the study carried out to evaluate combined effect of location of unbalance in individual components when they are assembled and work as a system. This study was carried out to assess the impact of change in of vibration pattern from Lateral to Vertical, Change of location of an eccentric mass, changes in acceleration/displacement pattern with different percentage of balancing
Julaha, Puneet, Arde, Vasundhara, Chirakkal, Remesan
Feasibility of Multiple Piston Motion Control Approaches in a Free Piston Engine Generator2019-01-259910/22/2019
The control and design optimization of a Free Piston Engine Generator (FPEG) has been found to be difficult as each independent variable changes the piston dynamics with respect to time. These dynamics, in turn, alter the generator and engine response to other governing variables. As a result, the FPEG system requires an energy balance control algorithm such that the cumulative energy delivered by the engine is equal to the cumulative energy taken by the generator for stable operation. The main objective of this control algorithm is to match the power generated by the engine to the power demanded by the generator. In a conventional crankshaft engine, this energy balance control is similar to the use of a governor and a flywheel to control the rotational speed. In general, if the generator consumes more energy in a cycle than the engine provides, the system moves towards a stall. If the generator consumes less energy, then the effective stroke, compression ratio and maximum translator velocity must rise steadily from cycle-to-cycle until the heat transfer losses stop the increase. Moreover, when stiff springs are added to the FPEG system, the dynamics becomes more sinusoidal and more consistent with increasing spring stiffness. To understand the behavior of proposed control and cycle-to-cycle variations, a comprehensive FPEG numerical model with a 1 kW target electric power was developed in MATLAB®/Simulink. An FPEG system corresponding to that numerical model has been operated in the laboratory. This MATLAB®/Simulink numerical model has been used to examine the sensitivity of FPEG dynamics and performance parameters to the changes in design and operating inputs. A difficulty during the modeling is associated with the cycle-to-cycle energy balance, and this difficulty is also reflected in the real-world FPEG control. Therefore, the authors have devised a control strategy similar to the real world intended control methodology. In this numerical model, two different feedback control methodologies were implemented and investigated. These control methodologies were applied to regulate the generator load with selected control or input variables, namely peak pressure, mid-stroke piston velocity, trapped compression ratio and dead center set points. The controllers with optimized coefficients demonstrated the feasibility of energy balance management during the transient operation. Based on the simulation results, the controllers with compression ratio, peak pressure and dead center clearance set points as control variables demonstrated stable FPEG operation whereas the mid-stroke velocity failed to achieve the steady-state operation due to deviation in the piston dynamics. The simulation results from this study will be used as the pathway for improving and optimizing the experimental FPEG design.
Bade, Mehar, Clark, Nigel, Famouri, Parviz, Guggilapu, PriyaankaDevi
Nondestructive Measurement of Residual Strain in Connecting Rods Using Neutrons05-12-03-001810/15/2019
Abstract Increasing the strength of materials is effective in reducing weight and boosting structural part performance, but there are cases where the residual strain generated during the process of manufacturing of high-strength materials results in a decline of durability. It is therefore important to understand how the residual strain in a manufactured component changes due to processing conditions. In the case of a connecting rod, because the strain load on the connecting rod rib sections is high, it is necessary to clearly understand the distribution of strain in the ribs. However, because residual strain is generally measured by using X-ray diffractometers or strain gauges, measurements are limited to the surface layer of the parts. Neutron beams, however, have a higher penetration depth than X-rays, allowing for strain measurement in the bulk material. The research discussed within this article consists of nondestructive residual strain measurements in the interior of connecting rods using the Second Generation Neutron Residual Stress Mapping Facility (NRSF2) at Oak Ridge National Laboratory (ORNL), measuring the Fe (211) diffraction peak position of the ferrite phase. The interior strain distribution of the connecting rod, which was prepared under different manufacturing processes, was revealed. By the visualization of interior strains, clear understandings of differences in various processing conditions were obtained. In addition, it is known that the peak width, which is also obtained during measurement, is suggestive of the size of crystallites in the structure; however, the peak width can additionally be caused by microstresses and material dislocations.
Ikeda, Tomohiro, Jeffery, Bunn R., Fancher, Christopher M., Motani, Ryuta, Matsuda, Hideki, Okayama, Tatsuya
Design and Analysis of Aluminium-Flyash Composite for Connecting Rod2019-28-016610/11/2019
In this modern era of rapid growth of technology and need of economical machining processes and materials, there is an increasing demand for new materials for different mechanical applications. Composites with fly ash as reinforcement are likely to overcome the cost barrier for wide spread applications in automotive and small engine applications. To improve wettability, elements such as Mg and Si are added into Al melt to incorporate the ceramic particles. The chemical composition and engineering properties of fly ash, its physical and chemical properties make it an ideal raw material for producing various application based composites. The main objective is to fabricate an Aluminium- Flyash composite material suitable for parts like engine connecting rod which demand high strength and temperature sustainability at comparatively less weight. The composite will be made using casting process and Engine connecting rod will be designed in AutoCAD software. The design will be analyzed with the help of Ansys with Aluminium and Aluminium- Flyash composite (at different compositions).
Nuthalapati, Suresh, Malkapuram, Devaiah
Design of Light Weight Hydraulic Connecting Rod for Agricultural Tractor2019-28-001610/11/2019
Hydraulic power train assembly of an agricultural tractor is meant to controls the position and draft of the implement depending upon the type of crop, farming stage, implement type and soil conditions. These variations induce extreme range of loads on the hydraulic system, thus making it challenging to design these components. Hydraulic connecting rod is critical component of hydraulic power train assembly. Standards like IS12224, IS4468 governs the design of hydraulic power train components which regulates the test method for hydraulic power and lift capacity of the tractor. In this paper, a virtual simulation process has been established to design a hydraulic connecting rod to meet the requirements. The hydraulic connecting rod basically functions as a short load transferring link, which is subjected to the operating hydraulic pressure of the hydraulic lifting mechanism. The current circular connecting rod is higher in weight and cost. So, there is scope for optimizing the design of connecting rod. Virtual simulation has been done by performing (i) Multi body dynamics analysis (MBD) approach is used to predict the loads on Tractor Hydraulic assembly and (ii) Static structural analysis for the durability. In the initial stage of analysis, topology optimization study has been performed to get the feasible shape. From the results of Optimization approach, parametric analysis was performed and finalized the design. Optimized design with Cross Ribbed structure is having uniform strength in all directions and meets the Design criteria. The final Optimized model achieved 40% weight saving over current design. Cross Ribbed structure of hydraulic connecting rod is filed for patent.
Dumpa, Mahendra, Perumal, Solairaj, Redkar, Dinesh, Gomes, Maxson, Subbaiyan, Prasanna Balaji
Design and Analysis of Hybrid Metal Matrix Composite Connecting Rod via Stir/Squeeze Casting Route2019-28-011310/11/2019
The connecting rod was manufactured by forging process for enhancing high tensile and compressive load so that it was followed by the machining process and suite the IC engine as a part of the component. The main intern of our proposed work is to manufacture a two set of composites specimen of A356 alloy with reinforcement of 5 wt.% silicon carbide and 10 wt.% flyash processed through two different techniques like stir casting and stir cum squeeze casting route and obtain better mechanical properties. Further, the same properties were taken for modeling and analysing of the developed connecting rod model. Due to the commercial demand, the hybrid composite materials take a vigorous role in the analysis part of the connecting rod model. The FEA analysis is done on the connecting rod for a180cc engine by using Ansys 18.1. The static analysis is done by considering four different cases by altering material library property. The output parameter such as total deformation, Von Mises stress, and maximum equivalent elastic strain are taken in each condition. The analysed results show that the material property of aluminium alloy A356 reinforced with 5% SiC and 10% flyash was cast under stir cum squeeze casting condition opt better results when compared with conventional stir casted connecting rod model and also the specimen of A356 alloy with reinforcement of 5 wt.% silicon carbide and 10 wt.% flyash under stir cum squeeze casting will have better material property.A356 reinforced with 5% SiC and 10% flyash will have better results and higher material property when compared with previous similar researchers. So this composites and process were recommended for manufacturing of connecting rod for automobile applications.
Ranganathan, Soundararajan, Kuppuraj, Sathishkumar, Soundarrajan, Karthik, Perumal, Ashokvarthanan
Performance Engine Building Recommended PracticesJ2379_201910 (Current)10/3/2019
This SAE Recommended Practice applies to the function of building reciprocating spark-ignition engines which are used in conjunction with standard and high-performance ancillary components in applications intended to achieve a minimum of 1 hp/in3. This document does not apply to rebuilt engines which may only be partially repaired with little or no machining, nor does it apply to second-hand or used engines.
Motor Vehicle Council
Modeling of a Spark Ignition Engine with Turbo-Generator for Energy Recovery2019-24-00849/9/2019
Increasingly stringent regulations in the field of pollutant are forcing engine manufacturers to adopt new solutions to contain exhaust emissions, such as Hybrid Electric Vehicles (HEV) or Full Electric Vehicles (FEV). Still far from the wide diffusion of FEV limited from electrochemical storage systems together with the difficulty of creating adequate infrastructure distributed throughout the territory to recharging batteries, the HEV seems to be actually a better solution. The hybrid vehicle is already able to guarantee satisfactory autonomy and low pollution levels by combining the advantages offered by the two technologies of thermal and electric propulsion. Currently on the market there are several types of hybrid vehicles, with different degree of hybridization (electric motor power versus propulsion total power), capacity to store electricity and type of scheme constructive adopted for the integration between the thermal engine and the electric machine. A particular interest is getting the mild-hybrid (or light hybridization) and the micro-hybrid (or minimum hybridization) with 48V electrical system added to the classic 12V one. A possible solution could be the electric turbo-compounding system where a turbine coupled to a generator (turbo-generator) uses the exhaust gas flow of a reciprocating engine to harvest waste heat energy and convert it into electrical power. In this way, the power generated from the system can be used to feed local electrical loads such as engine auxiliaries, increasing the whole system efficiency. The present study deals with the simulation of a spark ignition engine, present in a test room of Istituto Motori (CNR), including a turbo-generator at the exhaust to evaluate the advantages in terms of overall efficiency. The internal combustion engine model was developed by using a 1D code (GT-Power software), while the turbo-generator and the electric system are described in the Matlab/Simulink environment. The results obtained showed an appreciable increase in the overall efficiency.
Arminio, Fabio, Cameretti, Maria Cristina, De Simio, Luigi, Iannaccone, Sabato, Terzo, Teodoro
Piston Bowl Geometry Effects on Combustion Development in a High-Speed Light-Duty Diesel Engine2019-24-01679/9/2019
In this work we studied the effects of piston bowl design on combustion in a small-bore direct-injection diesel engine. Two bowl designs were compared: a conventional, omega-shaped bowl and a stepped-lip piston bowl. Experiments were carried out in the Sandia single-cylinder optical engine facility, with a medium-load, mild-boosted operating condition featuring a pilot+main injection strategy. CFD simulations were carried out with the FRESCO platform featuring full-geometric body-fitted mesh modeling of the engine and were validated against measured in-cylinder performance as well as soot natural luminosity images. Differences in combustion development were studied using the simulation results, and sensitivities to in-cylinder flow field (swirl ratio) and injection rate parameters were also analyzed. In-cylinder mixture formation analysis showed that ignition of the pilot injection mixture develops nearly as it would in a homogeneous adiabatic reactor, being mostly advected, not mixed, by the bowl’s swirling motion, while its timing is influenced by the local flow field. Details of the local in-cylinder flow are also more crucial than injection parameters in igniting the main injection’s premixed fuel, as it determines the relative overlap with the high-temperature pilot ignited mixture. Bowl geometry effects drive diffusive and late-cycle combustion, as structural differences of the main injection spray flames appear due to the different impact geometries at the piston bowl rim. However, these do not affect wall heat transfer significantly: it is dominated by the piston surface area. Better air utilization with the stepped-lip geometry, thanks to greater azimuthal spreading at the rim, a strong recirculating vortex in the squish region, and better mixing in the bowl, is responsible for better late-cycle combustion efficiency and lower soot emissions.
Perini, Federico, Busch, Stephen, Zha, Kan, Reitz, Rolf, Kurtz, Eric
Ford ‘cranks’ it up with another big V8 for Mustang19AUTP09_119/1/2019
When Ford introduced the Mustang Shelby GT350 in 2015, it was the pinnacle of Mustang-ness thanks to its 5.2-L DOHC “Voodoo” V8 that featured a flat-plane crankshaft design to enable sky-high revs (the GT350's 8200-rpm redline is one reason Ferrari has long specified flat-plane V8s) and a rollicking 526 hp at 7,500. Then there's the exotic “rip” exhaust note unique to flat-plane V8s. But contemporary musclecar development times seemingly are as quick as their ever-dropping 0-to-60 mph runs-and before Ford released the Shelby GT350, its SAE-certified 526 hp already had been eclipsed by the 707-hp supercharged 6.2-L Hemi V8 in the Dodge Challenger SRT Hellcat and later the 797-hp Hellcat Redeye. Prior to all this, GM's Chevrolet started the hyper-power frenzy by generating 650 hp from the supercharged 6.2-L OHV V8 launched for the 2012 Camaro ZL1.
Visnic, Bill
SAE 17.6 Cubic Inch Spark Plug Rating EngineJ2203_201906 (Current)6/11/2019
This SAE Standard defines the standard engine to be used in determining spark plug preignition ratings. The engine is known as the SAE 17.6 Cubic Inch Spark Plug Rating Engine.
Ignition Standards Committee
Characteristics of Bending Stress with Whirling at the Rear End of a Crankshaft in an Inline 4-Cylinder High Speed Diesel Engine2019-01-15926/5/2019
As engines become lighter and achieve higher output to meet carbon dioxide emissions targets, it becomes more challenging to design a crankshaft that is both lighter and capable of handling higher loads. Therefore, it is necessary to understand the characteristics of forces imposed on the crankshaft, and the mechanisms by which stresses are created in the crankshaft. This paper describes the characteristics of bending stresses measured on the rearmost crank pin fillet of a crankshaft. Two basic crankshaft resonant modes are described. Forward crankshaft whirl then has the effect of increasing the system natural frequencies by the stiffening effect, while reverse whirl reduces the system natural frequencies by the softening effect. The effect of whirl grows with increasing engine speed. This results in what appears to be four crankshaft natural frequencies rather than two. The four resonances appear at all non-zero engine speeds. The influence of flywheel mass on the stresses and natural frequencies is also described. It is shown that the bending stress in the crank fillet is proportional to the radial force acting on the crank pin. It is also shown that the direction of whirl affects the amplitude of stress imposed by the radial crank pin force, and that the effect of whirl becomes larger as the flywheel inertia is increased. Because increasing engine speed causes more whirl force and moment, engine speed has an influence on bending stress amplitude. Finally, the paper explains why the ratio of crank stress amplitude to radial force varies as a function of the rotational direction of whirl.
Kobayashi, Shinichiro
The Influence of Connecting-Rod Specifications on the Combustion-Noise Generation from a Diesel Engine2019-01-15906/5/2019
We experimentally investigated the influence of shifting natural frequencies of the internal transmission system depending on the connecting-rod specifications on the characteristics of noise radiated from a single-cylinder diesel engine. We used FFT analysis to investigate the influence of shifting natural frequencies of the internal transmission system on the radiated noise characteristics. By changing the thinned portion of the connecting-rod, we confirmed that the natural frequency of the piston-connecting-rod-coupled vibration differed from another natural frequency of the engine structure, and thus the engine noise was reduced. This research studied the time-frequency characteristics of combustion impact and engine noise by wavelet analysis of in-cylinder pressure and sound pressure. We examined the vibration-transmission characteristics through the relationship between the maximum engine noise power and the maximum combustion energy in the same cycle for the main frequencies of combustion noise. Two types of connecting-rods were used: the original connecting-rod and a connecting rod that has a short-thinned portion (STP). By shortening the thinned portion of the connecting-rod, the natural frequency of the piston-connecting-rod-coupled vibration became around 2800 Hz from 2500 Hz, and the vibration transmission efficiency, η, around 2500 Hz became small. By shortening the thinned portion of the connecting-rod, the decay rate, c, around 2500 Hz became large while the decay rate around 2800 Hz did not change.
Oguchi, Hitoshi, Minato, Koki, Seo, Takehiko, Mikami, Masato
Integrating a Proactive Quality Control Concept into Machining Operation of a Crankshaft Manufacturing Process2019-01-05074/2/2019
Competition in the manufacturing industry is ever increasingly intense. Manufacturing organizations that want to grow and prosper must embrace a discipline of constant improvement. Their engineering departments are tasked with improving existing manufacturing processes in terms of quality and throughput, which is vital to competing on a global scale. Manufacturers strive to utilize technologies to extract efficiencies from their existing processes. Reducing scrap and rework is the paramount goal in increasing a processes’ efficiency. The foundation of this study is to analyze a production line to determine the quality status throughout the manufacturing process. The intention is to react to process instability before the production becomes non-compliant (scrap/rework) which will significantly improve productivity. By incorporating the proposed technology into the production process, the desired achievement will be to spot process variables at the earliest stages so that counter measures can be taken to stabilize the process before production drifts into non-compliance. Furthermore, the technology will communicate with machining operations to initiate counter measures such as program offsets, tool changes and wheel dressings. The main goal of this study is to develop a system that will concurrently monitor the compliance of respective machining operations and automatically issue corrective actions to keep production in compliance much faster than the current system, which relies on production workers to acknowledge that the process is producing scrap of rework parts and then determine what corrective action to take.
Bazzi, Loda
Path-Averaged Temperature Measurement in a Motored Engine Cylinder Using Ultrasonic Thermometry2019-01-12444/2/2019
A limitation currently facing internal combustion engine research and development is the lack of a direct method to accurately measure in-cylinder temperature. The rate at which an engine cycle evolves is too rapid for conventional, direct measurement transducers such as thermocouples or thermistors. This paper presents the experimental results of a novel method for determining time-resolved in-cylinder temperature using ultrasonic thermometry. The technique involved sampling an ultrasonic signal reflected from the top of the moving piston and measuring piston position using an optical encoder connected to the engine crankshaft. The known flight distance and measured time of flight (ToF) was used to determine path-averaged temperature. ToF of the ultrasonic signal was precisely determined using an unscented Kalman filtering technique. Experiments were conducted using a motored (non-combusting) engine without compression at two engine speeds and three known intake temperatures. Results show that the method is capable of measuring temperature to within an accuracy of 10%. Repeated temperature samples over consecutive cycles had standard errors below 0.25% when a significant number of samples were available to analyze. Overall, our work proves that path-averaged, in-cylinder temperature measurement using ultrasonic thermometry is a feasible approach for use in engine research applications. With the availability of robust transducers that can withstand high temperature and pressure, we expect that the developed method can be applied to firing engines.
Weigelt, Chad, Northrop, William F.
Modeling of Oil Transport between Piston Skirt and Cylinder Liner in Internal Combustion Engines2019-01-05904/2/2019
The distribution of lubricating oil plays a critical role in determining the friction between piston skirt and cylinder liner, which is one of the major contributors to the total friction loss in internal combustion engines. In this work, based upon the experimental observation an existing model for the piston secondary motion and skirt lubrication was improved with a physics-based model describing the oil film separation from full film to partial film. Then the model was applied to a modern turbo-charged SI engine. The piston-skirt FMEP predicted by the model decreased with larger installation clearance, which was also observed from the measurements using IMEP method at the rated. It was found that the main period of the cycle exhibiting friction reduction is in the expansion stroke when the skirt only contacts the thrust side for all tested installation clearances. The main reason for lower skirt friction with larger clearance is greater amount of oil available during the expansion stroke.
Meng, Zhen, Ahling, Sebastian, Tian, Tian
Investigation and Optimization of Cam Actuation of an Over-Expanded Atkinson Cycle Spark-Ignited Engine2019-01-02504/2/2019
An over-expanded spark ignited engine was investigated in this work via engine simulation with a design constrained, mechanically actuated Atkinson cycle mechanism. A conventional 4-stroke spark-ignited turbo-charged engine with a compression ratio of 9.2 and peak brake mean effective pressure of 22 bar was selected for the baseline engine. With geometry and design constraints including bore, stroke, compression ratio, clearance volume at top dead center (TDC) firing, and packaging, one over-expanded engine mechanism with over expansion ratio (OER) of 1.5 was designed. Starting with a validated 1D engine simulation model which included calibration of the in-cylinder heat transfer model and SI turbulent combustion model, investigations of the Atkinson engine including cam optimization was studied. The engine simulation study included the effects of offset of piston TDC locations as well as different durations of the 4-strokes due to the mechanism design. Incremental effects of adjusted combustion phasing, scaled valve durations, to a fully optimized cam duration and phasing are determined, and the impacts of each discussed. A constant speed load sweep was conducted to compare the net indicated fuel conversion efficiency difference between baseline and Atkinson cycle engine. Besides, two speed load conditions (1300rpm, 3.3bar IMEPnet and 1750rpm and 10.3bar IMEPnet) with valve timing optimization were also investigated. Results from the study indicate that with an increase in the load from 4bar to 12bar IMEPnet at 2500rpm, over expansion contributed to an increase of 2.3% in net indicated efficiency. Furthermore, with valve optimization, negative work was avoided in the Atkinson cycle engine at 3.3bar IMEPnet, 1300rpm with an increase of 2% in the net indicated fuel conversion efficiency. At 10.3bar IMEPnet and 1750rpm, net indicated fuel conversion efficiency increased by 4.6%.
Yang, Zhuyong, Miganakallu Narasimhamurthy, Niranjan, Miller, Tyler, Naber, Jeffrey
Limitations of Sector Mesh Geometry and Initial Conditions to Model Flow and Mixture Formation in Direct-Injection Diesel Engines2019-01-02044/2/2019
Sector mesh modeling is the dominant computational approach for combustion system design optimization. The aim of this work is to quantify the errors descending from the sector mesh approach through three geometric modeling approaches to an optical diesel engine. A full engine geometry mesh is created, including valves and intake and exhaust ports and runners, and a full-cycle flow simulation is performed until fired TDC. Next, an axisymmetric sector cylinder mesh is initialized with homogeneous bulk in-cylinder initial conditions initialized from the full-cycle simulation. Finally, a 360-degree azimuthal mesh of the cylinder is initialized with flow and thermodynamics fields at IVC mapped from the full engine geometry using a conservative interpolation approach. A study of the in-cylinder flow features until TDC showed that the geometric features on the cylinder head (valve tilt and protrusion into the combustion chamber, valve recesses) have a large impact on flow complexity. As a result, errors in near-TDC swirl ratio, vortex structure and turbulence availability were seen when employing sector meshing, even if a 360-degree sector, with direct IVC flow mapping, was used. During injection, lack of geometric details on the head led to the inability to predict the formation of an upper recirculation region on the tumbling plane, above the piston step, which has been associated with thermal efficiency benefits with the stepped-lip bowl. Initialization of the flow anisotropies in the cylinder resulting from the intake process at IVC were instead seen to have a smaller effect. The results also showed that tuning IVC quantities in a sector mesh cannot effectively compensate for its missing geometric and flow details.
Perini, Federico, Busch, Stephen, Kurtz, Eric, Warey, Alok, Peterson, Richard C., Reitz, Rolf
Analysis of the Increase Level of Vibration in an Internal Combustion Engine due to the Degradation of the Lubricating Oil2019-01-07804/2/2019
When analyzing vibrations in internal combustion engines, it is noticed that the greatest sources of vibrations are generated by combustion and mechanical forces. These forces occur over a wide frequency range and are transmitted to the outer surface of the engine through several paths, such as through the piston mechanism, connecting rod, crankshaft and engine block. As a result of the action of these forces, the external surfaces of the engine are subjected to vibrations of various amplitudes. Vibration problems in internal combustion engines are common due to the wide variety of parts and components that make up such engines. The crankshaft undergoes transverse, longitudinal and torsional vibrations due to the dynamics of the stresses sustained mainly during the combustion phase of the engine. The effects of vibration produce premature wear on the internal components of the engine, which contributes both to reduce the lifespan of the engine itself as well as cause discomfort to the occupants of the vehicle. Thus, since it is impossible to totally eliminate vibrations from engines, it is important to understand the sources of vibration production and control them to acceptable levels. The objective of this work was to evaluate the vibration level of an internal combustion engine due to the degradation of the lubricating oil used in the engine. The level of vibration increases with the time of use of the lubricant, and that this increase is very significant from the moment the viscosity has reached the minimum limit stipulated by the lubricant manufacturer. The type of fuel and viscosity of the lubricant influence the level of vibration in the engine. The results show that engine running on ethanol with lubricant of lower viscosity have the highest rates of vibration.
Santana, Claudio Marcio, Mautone, Jose, almeida, helder
The Influence of IC Engine Working Condition on the Lubrication Characteristics of Piston Ring2019-01-05914/2/2019
The lubrication analysis of IC engine piston ring is usually carried out under engine rated working condition. In actual use, the IC engine (especially the vehicle engine) does not always operate in rated working condition, and its working condition will be changed frequently. In this paper, an IC engine is taken as the studying object, based on the measured gas pressure in the engine cylinder, the lubrication characteristics of piston ring under different engine working conditions is analyzed in which the transport of lubricating oil between the piston ring and the cylinder liner is considered. The results indicate that the engine working condition has remarkable influence on the lubrication characteristics of IC engine piston ring. The worst lubrication status of piston ring may not occurred in the engine rated working condition. Therefore, it is not enough comprehensive and reasonable to analyze the lubrication of piston ring only under engine rated working condition, but its lubrication under different working conditions needs to be analyzed in the design of IC engine piston ring.
Wang, Xing, Duan, Jinghua, Sun, Jun
A Framework for Model Based Detection of Misfire in a Gasoline Engine with Dynamic Skip Fire2019-01-12884/2/2019
A framework is proposed for model-based misfire detection in gasoline engines with dynamic skip fire by employing a novel control oriented engine model. The model-based techniques form compact description of plant behavior and have a number of well known benefits. The performance requirements and environment legislation resulted in a rigorous research on misfire detection due to which an extensive literature can be found for the problem of misfire detection in all-cylinder firing gasoline engines. Since there is no fix cylinder activation/de-activation sequence in dynamic skip fire engines. So, the problem of misfire detection in dynamic skip fire engines departs from its trivial nature. In the proposed framework, ‘cylinder skip sequence’ is also fed to the engine model along-with conventional engine inputs. The First Principle based Engine Model constructs the crankshaft angular speed fluctuation pattern for a given cylinder skip sequence. The crankshaft angular speed fluctuation pattern is shown for three cases which include, the conventional engine configuration, gasoline engine with dynamic skip fire and gasoline engine with dynamic skip fire having intermittent misfire condition. The simulation results are presented to show the efficacy of the proposed framework with the help of frequency domain components of the model output and normalized cross correlation during steady state and transient conditions.
Yar, Ahmed, Anjum, Raheel, Ahmed, Qadeer, Bhatti, Aamer
Generation of Optimized Rotation of Counterweights from Balancing Device for Slider-Crank Mechanisms2019-01-50203/26/2019
The main purpose of this work was to minimize the total unbalanced inertial forces generated by slider-crank mechanism during steady-state regime, developing the concept behind the Lanchester balancer. The goal approach was based on a kinematic scheme, which realizes conversion of the input crankshaft steady speed into a prescribed output speed of counter-rotating weights. The needed adaptability of output rotation speed was obtained through theoretical model of noncircular gear transmission. The dynamic result consisted in generating balancing forces that should have acquired optimized instantaneous magnitudes. A mathematical model of the required device was built and analytical investigation was performed in order to obtain geometrical features of gears. This mathematical approach supplied an exact solution for potential employment into the kinematic scheme. At this point a review of feasibility of obtained results was done. The scarcity of practical utility of previously obtained results requested another strategy to get to the target. Consequently the main problem was reformulated as Evolutionary Multi-objective Optimization (EMO) problem. Optimization method was based on Genetic Algorithms (GA) and lead to the best compromise that produced a numerical result entered into Computer-Aided Design (CAD) routines, for modelling of noncircular gears constituting the needed system. The open-source evolutionary computation library MOEA Framework was set as the work environment. It supports a variety of Multi-objective Evolutionary Algorithms, including GA, Genetic Programming, and Particle Swarm Optimization. These tools were applied in different tests in order to gain the most efficient way of optimization. NSGA-II was revealed experimentally as most appropriate algorithm. At the end of this study we do a practical employ of NSGA-II together with CAD implementations for synthesis of solid models. The overall benefit of resultant balancing action was estimated as 89% reduction in peak-to-peak amplitude of dynamic load.
Destradi, Giovanni
FCA debuts new Ram Heavy Duty pickups19AUTP03_163/1/2019
FCA's Ram truck division unveiled its new 2019 Heavy Duty (HD) pickup truck lineup at the 2019 North American International Auto Show (NAIAS). The new HD pickups feature the slick interiors and tech from Ram's new 1500 line, significant powertrain and chassis upgrades and all-new front and rear sheetmetal. The Ram HD lineup will face off against Chevy's new HD pickup offerings and Ford's established F-Series and includes 2500/3500 capacities in regular, crew and mega-cab configurations. Since it's a heavy-duty truck launch, Ram is of course touting new capability figures for its HD lineup, which retains its basic cab architecture, but sees nearly every other part of its chassis upgraded. A new 6.7-liter turbo-diesel producing 1,000 lb·ft of torque-the first HD pickup to break the fourfigure torque-output barrier-combines with a redone frame that's now 98.5% high-strength steel to provide what Ram claims are class-leading figures of 35,100-lb (15,921-kg) towing and 7,680-lb (3,565-kg) of payload.
Seredynski, Paul
2020 Ford Super Duty debuts all-new OHV V819AUTP03_173/1/2019
The 2020 Ford F-Series Super Duty will arrive with the heavy-duty pickup truck's best-ever conventional, gooseneck, and fifth-wheel trailer towing and payload ratings. “What makes these highest-ever ratings possible is our strongest-yet Super Duty powertrain offerings,” said Dave Filipe, Ford VP of global powertrain during the 2020 F-Series Super Duty's January 30 debut in Detroit. Automotive Engineering spoke with Ford powertrain engineers about the all-new pushrod V8, the third-generation 6.7-L Power Stroke diesel V8, and the all-new 10-speed TorqShift automatic transmission offered on the 2020 F-250, F-350, and F-450 trucks, which are expected to begin shipping to dealers in the fall of 2019.
Buchholz, Kami
Selection of Rational Parameters of Automated System of Robotic Transmission Clutch Control on the Basis of Simulation Modelling2019-01-00291/15/2019
The article deals with the analysis of one of the methods of selecting rational parameters of automated clutch control system for robotic transmission. The objective is to select rational parameters of automated clutch control system for robotic transmission, equipped with electropneumatic actuating mechanism on the basis of mathematical simulation. The depicted mathematical simulation of the clutch control system is characterized by the possibility to coordinate the algorithm of control unit with the dynamic processes in the execution device. The new functional interrelations between the elements of the electro-pneumatic actuator are mathematically described. The way to the selection of rational parameters of an automated control system for clutch is recommended; the selection taking into account the features of the electro-pneumatic actuator. Using the mathematical modeling method, rational control parameters of the automated clutch control system are determined. Based on comparative experimental researches, an inaccuracy is calculated for the mathematical modeling of the processes taking place in the electro-pneumatic actuator of a robotic transmission. Analysis of the results of mathematical modeling allowed finding factors that give a competitive advantage in comparison with automated clutch control systems that are used for commercial purposes.
Mikhalevich, Mykola, Yarita, Alexandr, Leontiev, Dmitry, Gritsuk, Igor V., Bogomolov, Viktor, Klimenko, Valeriy, Saravas, Viktoriya
Fuel & Lubricant Effects on Stochastic Preignition2019-01-00381/15/2019
In this multi-phase study, fuel and lubricant effects on stochastic preignition (SPI) were examined. First, the behavior of fuels for which SPI data had previously been collected were characterized in terms of their combustion and emissions behavior, and correlations between these characteristics and their SPI behavior were examined. Second, new SPI data was collected for a matrix of fuels that was constructed to test and confirm hypotheses that resulted from interpretation of the earlier data in the study and from data in open literature. Specifically, the extent to which the presence of heavy components in the fuel affected SPI propensity, and the extent to which flame initiation propensity affected SPI propensity, were examined. Finally, the interaction of fuels with lubricants expected to exhibit a range of SPI propensities was examined. Although this final dataset did not yield conclusive results, it suggests that additional factors such as engine condition can have a very significant effect on SPI propensity. The main findings of the study are that lower volatility fuel components appear to affect the propensity of the fuel to create initiation events (which could be fuel-oil droplets or deposit breakoff) that can lead to SPI, and further that the ease by which a flame can be established in the bulk mixture correlates to SPI tendency when the initiation event tendency is fixed. The study also showed that neither soot-forming tendency of a fuel nor the fuel’s antiknock quality necessarily correlate to SPI tendency.
Costanzo, Vincent S., Yu, Xin, Chapman, Elana, Davis, Richard, Haenel, Patrick
The Rotating Liner Engine (RLE) Diesel Prototype: Preliminary Testing2019-01-00841/15/2019
The Rotating Liner Engine (RLE) concept is a design concept for internal combustion engines, where the cylinder liner rotates at a surface speed of 2-4 m/s in order to assist piston ring lubrication. Specifically, we have evidence from prior art and from our own research that the above rotation has the potential of eliminating the metal-to-metal contact/boundary friction that exists close to the piston reversal areas. This frictional source becomes a significant energy loss, especially in the compression/expansion part of the cycle, when the gas pressure that loads the piston rings and skirts is high. This paper describes the Diesel RLE prototype constructed from a Cummins 4BT and the preliminary observations from initial low load testing. The critical technical challenge, namely the rotating liner face seal, appears to be operating with negligible gas leakage and within the hydrodynamic lubrication regime for the loads tested (peak cylinder pressures of the order of 80 bar).
Dardalis, Dimitrios, Hall, Matthew, Matthews, Ron, Basu, Amiyo, Ozel, Tayyar
Coupled Dynamic Simulation of Two Stage Variable Compression Ratio (VCR) Connecting Rod Using Virtual Dynamics2019-26-00311/9/2019
The fuel consumption of combustion engines requires continuous reduction to meet future CO2 fleet targets. The progression of emission legislations shifted the focus on PN and NOX emissions in real world driving scenarios (RDE). Recently, the monitoring of CO emissions puts high load fuel enrichment for component protection into focus and a ban on enrichment is widely expected. Hence, gasoline engine technologies, which enable Lambda 1 operation in the entire engine map are specifically promoted. Variable Compression Ratio (VCR) attacks all these topics already at the combustion process. In addition to the well-known CO2 capability, VCR also enables enlargement of the lambda 1 operation in gasoline engines as well as reduced NOX emissions in diesel engines. The basic principle of developed VCR solution is to change the effective length of the connecting rod (and thereby the compression ratio) in two stages by several millimeters. Basically, the VCR connecting rod consists of a mechanical and hydraulic system which is fed with oil by the connecting rod bearing. All functional elements to realize the variability such as an eccentric, lever, support rods, check valves and shift valve are integrated into the connecting rod. The system works without “external” energy supply but uses mass- and gas forces - acting on the piston pin - to vary its length. In order to analyze and optimize the system dynamics, a highly sophisticated simulation approach based on coupled simulations of the mechanical and the hydraulic subsystem of the VCR connecting rod. The co-simulation is carried out in time domain using the commercial software Virtual Dynamics for the elastic multi body simulations and GT-Suite for 1D fluid simulations. In this article the coupled 3D-multi body simulation/1D-hydraulic co-simulation as used to optimize the VCR connecting rod performance are presented.
Mane, Prashant, Pendovski, Denis, Sonnen, Sebastian, Uhlmann, Alexander, Henaux, Daniel, Blum, Ralf, Sharma, Vijay
Heavy capability for Chevy's 2020 Silverado heavy-duty pickups19AUTP08_181/1/2019
That there are a staggering eight different trim levels for the new 2020 Chevrolet Silverado HD lineup says much about the importance the commercial-pickup segment holds for each of the Detroit Three automakers. Like the half-ton pickups sold to everyday consumers, these models, once known mostly as “work trucks” have assumed a complex role that far exceeds their one-dimensional roots. The 2020 Silverado HD (2500/3500) line includes “just” five distinct trims, but there are sub-trims for three; all told, it's Work Truck, Custom, Custom Trail Boss, LT, RST, LT Trail Boss and High Country. As you work up the trim-level ladder, the line separating commercial duty and lifestyle accoutrement becomes blurrier-particularly when you understand it's possible to lay down nearly $90,000 for a check-all-the-boxes version of the new High Country trim.
Visnic, Bill
EXTENDING the ICE age19AUTP08_011/1/2019
Future vehicle propulsion is not a single-solution challenge. Top engineers take Automotive Engineering into the next combustion-engine frontier. Mass electrification is coming. By now, most of the mobility-engineering community accepts that. EVs will, at some point in time, emerge as a ubiquitous propulsion source for light vehicles-and potentially larger ones as well. But until that future arrives-maybe three decades hence-billions of new internal combustion engines of various types will be produced. Perhaps up to 3 billion more ICEs, depending on whose forecasting you believe. Increasingly they'll be paired with hybrid-electric systems. If even half of those new engines are four-cylinder types, that's 6 billion more pistons and connecting rods that'll need to be cast, forged and machined.
Brooke, Lindsay, Seredynski, Paul, Visnic, Bill
Mitigating Sound with Advanced Pump TechnologyTBMG-3324811/1/2018
Medical technology continues to evolve toward diagnosis and treatment devices that are closer to the patient, or even in the patient's home. Compression therapy, wound therapy, dialysis, point-of-care testing, and portable oxygen concentrators are just a few such instruments. Many of these instruments include active components that create noise that can impact a patient's sleep quality and level of comfort and can create stigma around using device. A diaphragm pump, which produces gas flow and pressure, is often one of the main sound contributors, and reducing the noise it makes can significantly affect the overall noise generated by the device. Engineers must balance performance needs and sound quality with increasing demands for miniaturized and application-specific equipment. These concerns have created a growing challenge to reduce the amount of noise generated by the device and its components.
Development of Horizontal Water Cooled Diesel Engine to Achieve High Power Density2018-32-006410/30/2018
The horizontal water cooled diesel engine has a structure including all component parts such as a fuel tank that are necessary to drive engine, and is often a single cylinder engine. It is mounted on many applications such as power tiller and water pump because of high general versatility of installing owing to belt drive. It has a simple structure because of single cylinder, and is active mainly in Southeast Asia. At the same time, the market requires this type of engine higher power while a compact structure is also required from the viewpoint of easy to supply and use. In other words, “High power density” that is improving the output per body size has been required. We have responded to the demand of “High power density” by increasing output without changing the engine size. In order to keep the engine size, we have been enlarging displacement by using our peculiar stroke-up expertise and original bore-up contrivance. In addition to those techniques, we introduced analytic technology for early approach to optimal solution. While we had used deep bowl combustion chamber for emphasizing medium and low speed torque, we adopted shallow dish combustion chamber because we shortened the compression height of piston for stroke-up. We utilized combustion analysis so as to approach optimal solution early because we have no base data of shallow dish combustion chamber. In addition, we used stress analysis to optimize the hardening of crankshaft. As written above, by incorporating analytic technology in addition to conventional development methods, we have been supplying correct size engines speedily in response to requirement of market. In this paper, we introduce the techniques that we adopted in order to realize the high power density.
Komai, Yoshinobu, Takashima, Yusuke, Fujiwara, Tsukasa, Okamoto, Hisao, Kawahara, Minoru
Performance Improvements to a Production, Semi Direct Fuel Injected, 2-Stroke Engine for a Racing Application2018-32-004310/30/2018
The following material presents an overview of using a production 2-stroke engine and transforming it into one for the racing application of Snocross. This paper will explore the changing of engine hardware, engine related hardware and software while staying within the project scope for schedule, tooling capabilities and rules of the governing body for Snocross racing. This conversion process is discussed in detail through analytical calculations, to the experimental validation with dynamometer and airflow bench data.
Olson, Andy, Hayes, Ryan
A Study of Friction Behavior of a Single Cylinder Gasoline Engine2018-32-007810/30/2018
In order to improve the performance, fuel economy and future emission norms of a reciprocating engine, it is important to reduce the overall engine frictional losses. In this paper, author conducts an experimental study on the friction characteristics due to pumping loss, valve-train system, piston assembly, auxiliaries and transmission for a 110cc, single cylinder 4-stroke gasoline engine using frictional strip-down analysis. This paper deals with the friction performance results for the new concept piston skirt design called the unsymmetrical skirt for least piston skirt friction. Also, parameters like piston profile, oil film thickness optimized for least friction. The piston profile is arrived for optimum contact pattern with least piston slap noise. The modified engine reduced the engine friction by 10% in comparison to the base engine.
Joseph, Sumith, Johnson, Jayajothi, Umate, Mohan D, Vipin, TS
Multi-Objective Optimization of Counterweights: A Substitute for the Balance Shaft or Mass Unbalancing in Three-Cylinder Engines03-11-05-003810/18/2018
Three-cylinder engines were launched, given the increasing demand for improved fuel economy and efficiency along with reduced friction and weight. Unlike four-cylinder engines, these engines are not naturally balanced. So, in order to compete with four-cylinder engines, some methods to solve this inherent weakness, such as balance shaft, mass unbalancing of flywheel and crankshaft pulley, or counterweights configuration (angular orientation and correction amount), have been used. Considering the undesirable characteristics of the balance shaft, such as cost, weight, friction, and noise, as well as dynamically inappropriate mass unbalancing method, this research proposes multi-objective optimization of counterweights to reduce vibrations. In this regard, after modeling a three-cylinder engine in constant speed and without the gas force effects, counterweights are optimized by non-dominated sorting genetic algorithm (NSGAII) method, to reduce shaking force, pitch and yaw moments, and bearing loads. Then possibility of removing the balance shaft and mass unbalancing, as the main purpose, with the help of counterweights is shown. Finally, a simple formula aimed at determining counterweights configuration to prevent the implementation of a long-term optimization process for each three-cylinder engine with a new specification is introduced. Due to the 92% reduction in pitching vibration for two similar engines, one with optimized counterweights and the other with mass unbalancing but more bearing loads, optimization is a more appropriate method. Also, with a reduction of about 80% of pitching vibration for two similar engines, one with optimized counterweights and the other with a balance shaft, along with the undesirable characteristics of the shaft, optimization is a good substitute for it.
Mohammadi, Somaye, Ohadi, Abdolreza
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