Browse Topic: Aluminum engines

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An Analytical Approach for Calculating Instantaneous Multilayer-Coated Wall Surface Temperature in an Engine2020-01-01604/14/2020
Thermal swing coatings that have low volumetric heat capacity and low thermal conductivity are attractive because they have the potential to significantly reduce heat transfer to the combustion chamber walls. This paper presents an analytical method for determining the exact solution of the time-resolved wall temperature during the engine cycle for any number of coating layers and properties using the Laplace transformed heat diffusion equation. The method relies only on material properties and the past heat flux history, and represents the exact solution of the heat diffusion equation. The analytical nature of the solution enables fast computation and, therefore, application to system-level optimization calculations. The model relies on an assumption of one-dimensional heat flow, and constant material properties. The major advantage of this approach compared to the standard finite difference approach, wherein the wall is finely discretized, is that there is no approximation and the accuracy is guaranteed, i.e., it does not depend on nodal density. Results are presented for both a quasi-steady operating condition and for an engine transient event. In the latter case a 200-fold reduction in computation time relative to a finite difference code was realized.
Koutsakis, G., Ghandhi, J.B.
Topology Optimization of an Engine Piston to Reduce Particulate Emissions during Cold Start Operation2019-01-08354/2/2019
The majority of engine out particulate emissions are released in the first several minutes of cold start operation, in large part due to cold piston surface temperatures which fall well below the boiling point of the injected fuel. Use of topology optimization methods to increase piston surface temperatures is a promising approach to solve this challenge, but existing applications have focused largely on basic small-scale canonical scenarios in the steady-state. In this work an algorithm was developed and demonstrated which is aimed at optimizing the internal structure of an engine piston to increase piston surface temperatures during the early phases of engine cold start, while subjected to a peak temperature limit during hot steady-state conditions. Finite difference heat transfer models of a light duty aluminum engine piston were created and an evolutionary optimization algorithm in conjunction with the Lagrange Multiplier Method were used to develop optimal piston topologies. Overall the methods developed represent a unique successful application of topology optimization techniques to an unsteady thermal system at a practical scale. Various optimal designs were generated and common geometric traits between them were identified, providing insight for future piston designs. The relationship between mean piston surface temperature after one minute of cold operation and maximum piston temperature during hot steady-state operation was quantified, defining optimal design limits and quantifying the trade-off between the two temperatures.
Mansfield, Andrew
Bearing and Bushing AlloysJ459_201801 (Current)1/10/2018
The bearing performance of steel backed half bearings, bushings, and washers is dependent on the properties and thickness of the lining alloy, the strength and dimensional stability of the steel backing (usually SAE 1010) and the strength of the bond between the lining alloy and the backing. This SAE Information Report is primarily concerned with the properties of the lining alloys used in automotive applications, in particular, the crankshaft bearings of the internal combustion engine.
Metals Technical Committee
Cylinder Head Thermo-Mechanical Fatigue Risk Assessment under Customer Usage2017-01-10863/28/2017
For aluminum automotive cylinder head designs, one of the concerning failure mechanisms is thermo-mechanical fatigue from changes in engine operating conditions. After an engine is assembled, it goes through many different operating conditions such as cold start, through warm up, peak power, and intermediate cycles. Strain alternation from the variation in engine operation conditions change may cause thermo-mechanical fatigue (TMF) failure in combustion chamber and exhaust port. Cylinder heads having an integrated exhaust manifold are especially exposed to this failure mode due to the length and complexity of the exhaust gas passage. First a thermo-mechanical fatigue model is developed to simulate a known dynamometer/bench thermal cycle and the corresponding thermo-mechanical fatigue damage is quantified. Additionally, strain state of the cylinder head and its relation to thermo-mechanical fatigue are discussed. The bench test was used to verify the TMF analysis approach. For field risk assessment, the customer usage profiles (customer image) are analyzed and corresponding duty cycles are built. A thermo-mechanical fatigue analysis approach based on transient cylinder head temperature history is developed for each customer usage duty cycle, and the corresponding strain alternation is translated to a thermo-mechanical fatigue life/damage. The risk of a cylinder head thermo-mechanical fatigue crack can be predicted from a customer image and related duty cycles.
Sever, Cagri, Brewer, Todd, Eeley, Scott, Chen, Xingfu, Jin, Ruichen, Khalil, Emad, Herr, Michael
New Coated Cast-In Liner to Improve Heat Transfer on Aluminum Blocks2016-36-026210/25/2016
Engine development activities are being driven forward primarily by the challenge of continuing to reduce CO2 and exhaust emissions. From the piston/liner system it is well known that Lube Oil Consumption (LOC) is affected by the bore distortion occurrences within Internal Combustion Engines (ICE) that usually demands a redesign on the piston ring pack not in favor to reduce friction losses. This article shows a potential solution to reduce bore distortion and oil evaporation through more efficient heat dissipation from combustion chamber to engine cooling system in a modern aluminum Spark Ignition (SI) block. Electroplated nickel coating applied to the external cast iron surface previous to the casting process enable a metallurgical diffusion layer with the aluminum block material and therefore improve heat conductivity in fired operation conditions compared to conventional cast iron liners. The improvement of the heat dissipation rate reduced the bore distortion and therefore LOC as proven by engine tests. In this paper, results of engine dyno tests to build up LOC maps using Real Time Lube Oil Consumption (RTLOC) by mass spectrometry are presented. The application of nickel coated liners showed LOC reduction up to 75% in certain engine operation conditions. Detailed information about the coating and diffusion layer of Fe-Ni-Al is also presented by Energy Dispersive X- Ray (EDS) and Scanning Electron Microscope (SEM). Finally comparative analysis of bonding strength on aluminum blocks and thermal conductivity measurements by thermocouples installed on aluminum blocks engine test is presented to consolidate the nickel coating technology.
Rejowski, Edney, de Souza, Juliano Pallaoro, Rabello, Rafael Bettini
Assessment of Residual Stress in T5 Treated 319 Aluminum Alloy Engine Blocks Using Neutron Diffraction2016-01-03534/5/2016
Aluminum alloys have been replacing ferrous alloys in automotive applications to reduce the weight of vehicles. The engine block is a striking example of weight reduction, and is made of Al-Si-Cu-Mg (319 type) alloys. The wear resistance in the engine block is enabled by cast iron liners, and these liners introduce tensile residual stress due to a thermo-mechanical mismatch. Typically, an artificial aging treatment effectively reduces residual stress. In this study, neutron diffraction was used to measure the residual stress profiles along the cylinder bridge of a T5 treated 319 aluminum alloy engine block. Results indicated high tensile residual stresses (200-300 MPa) in the hoop and axial orientation at depths of 50-60 mm below the head deck. The high residual stresses were likely due to a combination of minimal stress relief during artificial aging and stress development during post process cooling.
Ahmad, Suleman, Sediako, Dimitry, Lombardi, Anthony, Ravindran, C. (Ravi), Mackay, Robert, Nabawy, Ahmed
Investigation into Mixed and Hydrodynamic Frictions of PEO Coatings and Cast Iron2016-01-04914/5/2016
A linerless aluminum (Al) engine block has potential to reduce the weight of an automotive engine and improve the fuel economy. However, the Al cylinder surface of an aluminum engine block is not usually strong enough to withstand the sliding wear against piston rings. A few surface processing technologies are used to protect the surface of cylinders. Among them, a thermal spraying coating, such as plasma transferred wire arc (PTWA) is already popular. Plasma electrolytic oxidation (PEO) coating is also proposed for increasing the wear resistance of aluminum-silicon (Al-Si) alloys and reducing the friction between the cylinder and piston. In this work, two different PEO coatings with a thickness of around 23 μm were prepared on an Al-Si alloy A356, and a high speed pin-on-disc tribometer was used to study the tribological behavior of the coatings at oil lubricant conditions. A cast iron sample was also used to do similar tribological tests for comparison. The coefficient of friction (COF) vs surface roughness (Ra: 0.2 - 0.8 μm) and sliding speeds (up to 6.07 m/s) were particularly studied. The results show that the COF significantly decreased with the increase of sliding speeds, and a smoother coating surface generally exhibited a lower COF and a steeper descent rate of the COF. While such observations seem true for both PEO coatings and the cast iron sample, the polished PEO coatings can have a lower COF than cast iron. The study indicates that the Al-Si alloy with PEO coatings could be further explored as a feasible solution to reduce the weight and improve the fuel efficiency of an Al engine.
Wang, Guang, Nie, Xueyuan, Tjong, Jimi
MMLV: Aluminum Cylinder Block with Bulkhead Inserts and Aluminum Alloy Connecting Rod2015-01-12384/14/2015
The Multi Material Lightweight Vehicle (MMLV), developed by Magna International and Ford Motor Company, is a result of US Department of Energy project DE-EE0005574. The project demonstrated the lightweighting potential of a five-passenger sedan while maintaining vehicle performance and occupant safety. Prototype vehicles were manufactured and limited full-vehicle testing was conducted. The Mach-I vehicle design, comprised of commercially-available materials and production processes, achieved a 364 kg (23.5%) full-vehicle mass reduction. This resulted in environmental benefits and fuel economy improvements. A significant factor in the overall MMLV mass reduction was the decrease in the powertrain system weight from 340 kg (conventional) to 267 kg (MMLV). This enabled the application of a 1.0-liter three-cylinder engine as the main powerplant. By downsizing the engine, and by implementing material changes within the engine, the weight of the dressed engine was lowered by 29 kg. This paper examines the results from studies performed on two key MMLV powertrain components: an aluminum engine block with steel bulkhead inserts; and a connecting rod forged using a high-strength aluminum alloy. Both can yield significant weight savings compared to their conventional iron and steel equivalent components. For the MMLV, a small-displacement, high-output engine was desired for the powertrain. Based upon a prototype1.0L I3, the MMLV variant was cast in aluminum instead of gray iron. As the aluminum block structure was not sufficient to carry the loads associated with operation, reinforcement was needed. A bulkhead insert (patent-pending) was designed to carry the loads from the head deck through to the crankshaft area while maintaining stable thermal growth characteristics in the main crank journal. The optimum geometry of the insert was found to have an I-beam cross-section; macro-serrations were added to enhance the bond between the block and bulkhead insert. This study found that the cast aluminum block with the bulkhead inserts reduced the weight of the I3 block by 9.5 kg; this represents a 42% savings compared to a block cast in iron. The study also determined that bulkhead inserts can be designed to carry 95% of the main bearing loads generated from the combustion process. Additionally, the casting process allowed for a high interfacial bond to develop between the block and insert. Finally, a bulkhead fatigue bench test was used to validate the design and accurately predict failure location in the bulkhead insert. The results of the study have been used to guide a decision to continue the evaluation of the aluminum block with bulkhead inserts. The aluminum connecting rod study found that, with a careful selection of material and processes, it is feasible to produce aluminum connecting rods for high volume OEM vehicles. Further, the study found that a recently developed high-temperature, high strain-rate forging process does improve the ductility and fatigue strength of a 2618-T6 aluminum alloy. CAE analysis was used to confirm that a connecting rod can be designed using the 2618-T6 alloy to meet fatigue safety factor as well as clamp load and fastener requirements. The analysis determined that the Al alloy reduced the weight of a connecting rod by over 200 g (for a total saving of 700 g for the I3 engine); this represents a weight savings of 40% compared to conventional steel alloy rods. As with the block, the initial study on the aluminum connecting rod indicates that further material, design, and component verification is warranted.
Maki, Cliff, Byrd, Kevin, McKeough, Bryan, Rentschler, Robert G., Nellenbach, Brian J., Williams, Rick L., Boileau, James M.
Effect of Surface Roughness and Sliding Velocity on Tribological Properties of an Oxide-Coated Aluminum Alloy2014-01-09574/1/2014
Aluminum engines have been successfully used to replace heavy gray cast engines to lighten the car's weight and reduce the fuel consumption. To overcome the aluminum alloys' poor wear resistance, cast iron liners and thermal spraying coatings were used as cylinder bore materials for wear protection. A plasma electrolytic oxidation (PEO) technique had also been proposed to produce an oxide coating on aluminum cylinder bore. The oxide coating can have a low coefficient of friction (COF) and minimum wear shown in the lab tests. To conserve more fuel, the stopping and restarting system was introduced when the vehicle was forced to stop immediately for a short time. When the engine was forced to stop and restart, the reciprocating speed of the piston was very slow, and the friction between the piston and the cylinder was high. In this research, a pin-on-disc tribometer was used to investigate tribological behavior of the oxide coating on an aluminum alloy. The rotational velocity of the tribometer was increased stepwise in a low speed range during the tests. The COF and wear of counterface pins were measured and evaluated corresponding to different combinations of sliding velocities. The results showed that the COF could be affected by many factors such as coating composition, surface roughness, amount of lubricating oil and sliding velocity. With the increase of velocity in the low speed range, the COF decreased. The smoother of the coating surface, the less wear of counterface pin. A proper combination of coating surface roughness and sliding velocity could provide a significant lower COF and less wear.
Wang, Guang, Nie, Xueyuan
Residual Stress Mapping along the Cylinder Bores of Al Alloy Engine Blocks Subjected to Production Solution Heat Treatment Schedule2014-01-08374/1/2014
The development of an optimized heat treatment schedule, with the aim of maximizing strength and relieving tensile residual stress, is important to prevent in-service cylinder distortion in Al alloy engine blocks containing cast-in gray iron liners. However, to effectively optimize the engine block heat treatment schedule, the current solutionizing parameters must be analyzed and compared to the as-cast condition to establish a baseline for residual stress relief. In this study, neutron diffraction was carried out to measure the residual stress along the aluminum cylinder bridge following solution heat treatment. The stresses were measured in the hoop, radial and axial orientations and compared to a previous measured as-cast (TSR) engine block. The results suggest that solution heat treatment using the current production parameters partially relieved tensile residual stress in the Al cylinder bridge, with stress relief being more effective near the bottom of the cylinder.
Lombardi, Anthony, Sediako, Dimitry, Ravindran, C. (Ravi), Mackay, Robert
Full-Scale Burn Test of a 2001 Full-Size Pickup Truck2013-01-02144/8/2013
Temperature measurements during a full-scale burn test of a 2001 full-size pickup truck showed that the fire progressed in distinct stages in both the engine and passenger compartments. Although the fire started in the engine compartment and had a relatively long growth period, when a localized area reached about 700°C, a distinct transition occurred where the rate of fire spread increased, leading to full involvement of all engine compartment combustibles. As the engine compartment became fully involved, a hot gas layer then accumulated at the ceiling of the passenger compartment, producing a strong vertical temperature gradient. When the temperature at the ceiling reached about 600°C, another distinct transition occurred where the rate of fire spread increased, leading to full involvement of the passenger compartment. The highest temperature during the test occurred within the engine compartment in an area that had the greatest fuel load, and not the area of origin. Although oxidation and melted aluminum patterns were created during the fire, neither was useful in identifying the area of origin of the fire.
Colwell, Jeff D.
Analysis of Residual Strain Profiles in Distorted Aluminum Engine Blocks by Neutron Diffraction2013-01-01714/8/2013
In recent years, light weight components have been an area of significant importance in automotive design. This has led to the replacement of steel and cast iron with aluminum alloys for many automotive components. For instance, Al-Si alloys have successfully replaced nodular and gray cast iron in the production of large automotive components such as engine blocks. However, excessive residual strain along the cylinder bores of these engine blocks may result in cylinder distortion during engine operation. Therefore, in this study, neutron diffraction was used to evaluate residual strain along the aluminum cylinder bridge and the gray cast iron liners of distorted and undistorted engine blocks. The strains were measured in the hoop, radial, and axial orientations. The results suggest that the residual strain along the aluminum cylinder bridge of the distorted engine block was tensile for all three measured components. Conversely, the undistorted engine block had compressive strains in the axial and radial orientations, while the hoop direction had tensile strain of lower magnitude. The gray iron liners, meanwhile, had compressive residual strain for both engine blocks. The variation in strain, specifically in the aluminum cylinder bridge, suggests that permanent dimensional distortion in the cylinders was triggered by tensile residual stress when exposed to service conditions.
Lombardi, Anthony, Ravindran, Comondore (Ravi), Sediako, Dimitry, Mackay, Robert
Neutron Diffraction Study on Residual Stress in Aluminum Engine Blocks Following Machining and Service Testing2012-01-01884/16/2012
Development of lightweight alloys suitable for automobile applications has been of great importance to the automotive industry in recent years. The use of 319 type aluminum alloy in the production of gasoline engine blocks is an example of this shift towards light alloys for large automobile components. However, excessive residual stress along the cylinder bores of these engine blocks may cause problems during engine operation. Therefore, in this study, neutron diffraction was used to evaluate residual stresses along the aluminum cylinder bridge and the gray cast iron liners. The strains were measured in the hoop, radial, and axial orientations, while stresses were subsequently calculated using generalized Hooke's law. The results suggest that the residual stress magnitude for the aluminum cylinder bridge was tensile for all three measured components and gradually increased with cylinder depth towards the bottom of the cylinder. The residual stress in the gray cast iron liner was highly compressive with a relatively constant stress magnitude.
Lombardy, Anthony, Sediako, Dimitry, D'Elia, Francesco, Ravindran, C. (Ravi), Mackay, Robert I.
Friction Reduction in Power Cylinder Systems for Downsize Gasoline Engines with Modern Surface Technologies of Aluminum Crankcases2012-01-13324/16/2012
Downsized gasoline engines for passenger cars requiring low CO₂ emissions trend to lightweight designs using AlSi material for crankcases. For ultra-low vehicle fuel consumption a low friction and lightweight power cylinder system (PCS) has been developed containing a new lightweight piston design and current cylinder surface technologies such as structured honed AlSi or iron spray coating (PTWA) as well as related piston ring surface technologies such as DLC and PVD coatings. Component and system analysis for optimizing the design, materials used and design features are reviewed, along with PCS functionality, NVH and friction testing results. The breakdown to component friction reduction is summarized using synergies from friction simulation and engine friction measurement.
Hanke, Wolfgang, Fahr, Matthias, Rehl, Andreas, Voigt, Marco, Ando, Hajime
Modeling and Analysis of Powertrain NVH2012-01-08884/16/2012
Current modeling techniques of the powertrain noise, vibration and harshness (NVH) involve fully meshed structural components and rely, in general, on predefined excitation loads to evaluate linear transfer or structural attenuation functions. While effective for comparative assessment of various designs, these methods neglect the complex dynamic interactions between the powertrain structure and crankshaft, piston, valve train, timing drive, and accessory drive systems. This paper presents an overview of modeling methods of low and high frequency powertrain NVH with focus on dynamic interaction among structural components. A coupled and fully flexible multi-body dynamics model using AVL/Excite is presented. The model includes the cranktrain, crankcase, cylinder head, covers, oil pan, mounts, and transmission housing represented as finite element meshes. The main bearings are represented using elasto-hydrodynamic joints to account for the effect of oil film stiffness and damping as well as bearing clearance. The structural components are reduced using component mode synthesis and used to determine dynamic loads at various engine speeds and loading conditions. The main excitation sources relevant for both low and high frequency NVH and the influence of cylinder pressure, bottom end design, and crankshaft stiffness are discussed. An overview of piston related noise and modeling techniques to identify the causes and mechanisms leading to excessive impact noise in a floating piston pin design are presented.
Beloiu, Dumitru M.
Modelling of the Warm-up of a Spark Ignition Engine: Application to Hybrid Vehicles2011-01-17478/30/2011
One of the main advantage of a hybrid thermal-electric vehicle is that the internal combustion engine (ICE) can be shut down when not needed anymore (Stop&Start system, propulsion with full-electric mode), thus reducing fuel consumption. But this use of the ICE impacts its thermal behavior because of a lack of heat source and thermal losses. Furthermore, the ICE is sometimes used with higher load in order to charge the batteries that increases the total heating power produced by the combustion. Therefore, the simulation of hybrid vehicles becomes really interesting to evaluate the effect of different control strategies (energy repartition between the engine and the electric motor) on the fuel consumption. However, in most of actual hybrid vehicles simulation tools, for calculation speed reasons, the thermal phenomena are either not taken into account, or their calculation is not based on physical equations (empirical formulas). Their predictive capability is then limited. The global aim of this study is the development of a simulation tool (using the Amesim® software) for hybrid electric vehicle which takes into account most of the thermal phenomena occurring in the various components and between them without increasing the calculation time. In this paper, we first focus on thermal phenomena occurring in the spark ignition ICE. The coupling of a combustion model with a thermal model of the engine cooling system and its metal parts allows a simulation of its warm-up after a cold start. The thermal transfers between the different thermal inertia are computed and their dependence with different parameters like speed or load is evaluated. Research about the heating speed of the cooling water and the lubricating oil (due to the viscous friction and dependent of the global thermal state of the ICE) are interesting in order to find the best use of the ICE and therefore reducing the fuel consumption. Finally, the model of the engine including the thermal transfers is integrated in a simulation of the whole vehicle. The thermal behavior of two vehicles (a conventional and a parallel hybrid electric) using the same spark ignition engine is finally presented. The first results show that the thermal phenomena have a significant impact on the final consumption of the vehicles.
Dubouil, R., Hetet, J. F., Maiboom, A.
Compacted Graphite Iron - A Material Solution for Modern Engine Design2011-01-10834/12/2011
The demands for improved fuel economy, performance and emissions continue to pose challenges for engine designers and the materials they choose. The present paper provides a review of the properties of Compacted Graphite Iron (CGI), gray cast iron and aluminum and shows how the superior mechanical properties of CGI can contribute to engine design and performance. Based on production experience in Europe, Asia and the Americas, the application of CGI can provide new opportunities for reductions in engine weight and package size, increased specific performance together with improved durability, and improved NVH. Despite the density difference between CGI and aluminum, the ability to make a more compact cylinder block when using CGI often results in a fully assembled CGI engines that weigh less than an aluminum engines of the same displacement. This design opportunity is illustrated with specific examples of V6 and V8 diesel engines that are currently in production. The paper also provides a well-to-wheels energy comparison for CGI and aluminum, showing a favorable profile for cast iron cylinder blocks.
Dawson, Steve
2-Stroke Diesel Engine for Light Aircraft: IDI vs. DI Combustion Systems2010-01-214710/25/2010
The paper presents a numerical study aimed at converting a commercial lightweight 2-Stroke Indirect Injection (IDI) Diesel aircraft engine to Direct Injection(DI). First, a CFD-1D model of the IDI engine was built and calibrated against experiments at the dynamometer bench. This model is the baseline for the comparison between the IDI and the DI combustion systems. The DI chamber design was supported by extensive 3D-CFD simulations, using a customized version of the KIVA-3V code. Once a satisfactory combustion system was identified, its heat release and wall transfer patterns were entered in the CFD-1D model, and a comparison between the IDI and the DI engine was performed, considering the same Air-Fuel Ratio limit. It was found that the DI combustion system yields several advantages: better take-off performance (higher power output), lower fuel consumption at cruise conditions, improved altitude performance, reduced cooling requirements. Furthermore, the injection system requirements for DI combustion can be met also by mechanical pump and injectors.
Mattarelli, Enrico, Paltrinieri, Fabrizio, Perini, Federico, Rinaldini, Carlo Alberto, Wilksch, Mark
Engine Reliability Through Infant Mortality Mitigation: Literature Review2010-36-004910/6/2010
Internal combustion engines are designed to meet the high power, low fuel consumption and also, low exhaust emissions. The engine running conditions is valid the concept that, the expectative is very high because of the variety of operating conditions like cold start, frequent start and stop, time high speed and load, traditional gasoline, mix of gasoline and alcohol and finally, alcohol fuel only. Considering such demand, this paper explains the relationship between the reliability bathtub curve, specifically the "Infant Mortality" portion. The bathtub curve describes failure rate as a function of time. The "Infant Mortality" portion of the curve is the initial section for which the failure (death) rate decreases with time (age). In general, these problems are related to manufacturing aspects or poor design definitions. With development of technology, hard failures, the ones that cause dependability, are becoming rare. On the other hand, soft failures, the ones that cause poor customer perception, are increasing with competition and customer high demand. This paper focuses on a literature review of these two categories, approaching firstly the mechanisms of failures and secondly, a short description of the basic concepts. Also, a special emphasis is given to engine noises. Throughout this discipline to understand the failure mechanism and then, the basic concepts, it is expected to: 1) concentrate on perfect systems, not perfect components, 2) understand interaction failure modes and finally 3) do not pack more functionality into one button just because you can, the paper discusses the relationship with engine typical failure modes. In addition, better advanced quality plans and control plans can be performed.
Andreassa, Mauro C.
Evaluation of Cylinder Head Bolts for Torque - Tension Characteristics for Ensuring Sealing Performance of Single Layer Steel Gasket2010-01-13154/12/2010
IC Engine manufacturers are constantly in pursuit of better sealability of cylinder head and engine block interface for meeting performance and durability targets. In order to overcome variation in torque - tension characteristics of cylinder head bolt because of friction variations, yield based clamping are being extensively adopted. Current study is done on torque - tension characteristics of a cylinder head bolt with a controlled quality. The paper enumerates the experimental setup representing a sub 1 liter all aluminum engine's head-block joinery. Studies on torque - tension characteristics of cylinder head bolt and the effect of sealing interface using a cost effective single layer steel gasket are being discussed in the paper. Subject work has led to a successful implementation of angular torque parameters on head bolts to meet functional and durability targets.
Gopal, Manish, Varatharajan, Senthilkumaran, Gokhale, Kedar
Advanced Lost Foam Casting Processes and Materials2009-01-02134/20/2009
The lost foam casting process (LFCP) is a near-net shape casting process. This process is the most energy efficient casting process available. “Foundry Management and Technology” magazine analyzed the lost foam process and reported a 27% energy savings, a 46% improvement in labor productivity and 7% less material usage compared to other casting processes. The LFCP produces high value parts by combining multiple components into single castings, improving energy efficiency by achieving better metal yields, reducing materials consumption by eliminating cores, providing minimal post casting processing and improving as-cast dimensional accuracy. All of these process features reduce the total energy consumed during manufacturing. Advanced lost foam casting processes (Pressure Assisted Solidification and Vacuum Assisted Mold Filling) have demonstrated the capability to improve mechanical properties, especially fatigue performance, for aluminum alloys and improve casting cleanliness, which reduces scrap, for ferrous alloys. Advantages of LFCP that have not been fully utilized are 1) freedom from gray iron “skin” formation in ductile and compacted graphite iron and 2) elimination of hot tearing for high strength, cast aluminum alloys. These advantages, combined with the inherent near-net shape capability of the LFCP, would allow the economical production of lightweight, high strength and/or high stiffness automotive engine components, such as cylinder blocks and cylinder heads. These components would have a significant effect on vehicle fuel economy by allowing the production of diesel engines with lighter weight, greater performance and lower cost than currently possible.
Druschitz, Alan P., Littleton, Harry
Nondestructive Characterization of Residual Stresses on Cylinder Liners and Blocks via X-ray Diffraction Techniques2009-01-04234/20/2009
It is well known that machining operations produce surface conditions that can either enhance or debit the fatigue life of production components. Furthermore it has been well established that the thermal gradients produced during the solidification process of a casting operation can also generate detrimental residual stress loads. Cast cylinder blocks can sustain life limiting stress gradients from these processes. Due to their complex geometry it has historically been very difficult if not impossible to fully characterize the residual stresses present at critical locations in cylinder blocks. Recent advances in x-ray diffraction (XRD) have reduced the minimum clearance required for an accurate measurement from 200mm to 70mm. This now allows XRD to be used as a non destructive test (NDT) on features such as cylinder liners and bores, bulk heads and assembled journals. These advancements will allow OEM's and their suppliers to improve fatigue life and product quality by characterizing and managing the residual stresses present at various stages of production. Beyond production this technology will allow OEM's to measure residual stresses at different stages of a blocks operational life. Such information can be used to help design engine blocks with superior performance and life expectancy.
Ladouceur, J., Pineault, J., Brauss, M.
Improving Upon Best Available Technology: A Clean Flex Fuel Snowmobile2008-32-00499/9/2008
The University of Wisconsin-Madison Snowmobile Team has designed and constructed a clean, quiet, high performance snowmobile for entry in the 2008 Society of Automotive Engineers' Clean Snowmobile Challenge. Built on a 2003 cross-country touring chassis, this machine features a 750 cc fuel-injected four-stroke engine equipped with a fuel sensor which allows operation ranging from regular gasoline to an 85% blend of ethanol and gasoline (E85). The engine has been customized with a Mototron control system which allows for full engine optimization using a range of fuels from E00 to E85. Utilizing a heated oxygen sensor and a 3-way catalyst customized for this engine by W.C. Heraeus-GmbH, this sled reduces NOx, HC and CO emissions by up to 89% to an average specific mass of 0.484, 0.154, 4.94 g/kW-hr respectively. Finally, the Mototron system also allowed Wisconsin to extract another 4 kW from the Weber 750cc engine; producing 45 kW and 65 Nm of torque. A two stage muffler system along with sound absorbing material under the hood combines to reduce the sound levels to 71 dbA using SAE test procedure J192. The entire engine and two-stage muffler system is packaged in a manner that maintains the snowmobile's aggressive OEM appearance.
Rakovec, Nicholas, Olenski, Brian, Maney, Michael, Bower, Glenn R.
Numerical Analysis of Thermal Growth of Cast Aluminum Engine Components2008-01-14194/14/2008
As-cast or as-solution treated cast aluminum A319 has copper solutions within its aluminum dendrite. These copper solutions precipitate out to form Al2Cu through a sequence of phase changes and bring with them volume changes at elevated temperatures. These volume changes, referred to as thermal growth are irreversible. The magnitude of thermal growth at a material point is decided by the temperature history of the material point. When an under aged or non heat treated cast aluminum is exposed to non-uniform temperature such as that during engine operation, thermal growth leads to non-uniform volume change and thus additional self balanced stresses. These stresses remain inside material as residual stresses even when the temperature of the material is uniform again. In the present paper, numerical analysis method for thermal growth is developed and integrated into engine operation analysis. A user subroutine is written to interface thermal growth theory with commercial finite element code ABAQUS. The impact of thermal growth on durability of an engine cylinder head is illustrated by a real case study.
Chen, Xingfu, Su, Xuming, Gustafson, Peter, Allison, John
Chrysler Engines, 1922-1998R-36510/26/2007
Weertman, Willem L.
Rubber Peeling Mechanism of SOFT METAL ® for CHG2007-01-15194/16/2007
SOFT METAL (SUS plate coated with rubber) is used for cylinder head gasket (CHG). Conventionally, this SUS plate is preprocessed using coating chromate. When this was changed to chrome-free agent, the rubber was peeled off from the plate. There are found that this may be due to the electrochemical reaction caused by the contact between different metals-Al of the engine block and Fe (SUS) of CHG.
Kanamori, Masaaki, Tokumitsu, Hideyuki
Lexus LS 460:AEI's Best Engineered Vehicle for 2007AUTOAPR07_034/1/2007
The fourth generation of Lexus' global flagship sets new standards in engineering, technical innovation, refinement, and workmanship. “Yet again, Toyota demonstrates excellence in execution, not only in the basics, but also in the introduction of new active safety technologies in advance of their competitors,” one reader wrote, in describing the Lexus LS 460, Automotive Engineering International's Best Engineered Vehicle for 2007. “Transmission, engine, steering, chassis, fuel system, and driver monitoring systems are all new-and represent significant advances over the previous model,” said another.
Yamaguchi, Jack
NASA Personal Air Transportation Technologies2006-01-24138/30/2006
The ability to personalize air travel through the use of an on-demand, highly distributed air transportation system will provide the degree of freedom and control that Americans enjoy in other aspects of their life. This new capability, of traveling when, where, and how we want with greatly enhanced mobility, accessibility, and speed requires vehicle and airspace technologies to provide the equivalent of an internet PC ubiquity, to an air transportation system that now exists as a centralized hub and spoke mainframe NASA airspace related research in this new category of aviation has been conducted through the Small Aircraft Transportation (SATS) project, while the vehicle technology efforts have been conducted in the Personal Air Vehicle sector of the Vehicle Systems Program. The PAV sector technology research conducted over the past several years is described, including intelligent avionics for ease of use, integrated low noise propulsion, advanced internal combustion engines, low cost variable pitch ducted propellers, lean design structures, quality assurance based certification regulations, a laminar flow fuselage with integrated aero-propulsion, advanced vehicle concepts, and high density airspace simulations.
Moore, Mark D.
A Prediction of Weight Reduction and Performance Improvements Attainable through the use of Fiber Reinforced Composites in I.C. Engines2005-01-369310/24/2005
Fiber Reinforced Composites (FRCs) offer the possibility for reduced mass and increased performance in internal combustion engines, yet the automotive and aerospace industries have been slow to adopt these materials. Extensive research has been done over the past 25 years, producing nearly every components of an internal combustion engine out of some form of FRC. This Previous work is summarized herein. A prediction of engine weight reduction is made for direct substitution of FRCs. An additional prediction is made to quantify the additive effects of mass reduction on component mass, and power. It is estimated that engine mass might be reduced by as much as 70% using FRCs and reciprocating mass might be reduced by as much as 90%. In addition, increased mechanical efficiency on the order of 2% may be possible from reduced inertial and frictional loads.
Buckley, Richard T., Stanglmaier, Rudolf H., Radford, Donald W., Willson, Bryan
Effect of HPDC Parameters on the Performance of Creep Resistant Alloys MRI153M and MRI230D2005-01-03344/11/2005
The growing demand for the use of magnesium alloys in the production of automotive powertrain components led to the development of creep resistant diecasting alloys MRI153M and MRI230D. The present paper addresses the main high-pressure die casting parameters, which significantly affect the performance of components, produced of these new alloys. A systematic study was carried out in order to correlate die-casting parameters to the performance of new alloys. The results obtained clearly indicated that optimization of molten metal and die temperatures, injection profile parameters and lubrication mixtures allowed to improve the die castability and service properties of the new alloys and produce high performance components with intricate geometry. This was manifested by production of several practical demonstrators such as gearboxes, oil pans, oil pumps and crankcases.
Gertsberg, G., Nagar, N., Lautzker, M., Bronfin, B., Moscovitch, N., Schumann, S.
Coined Stopper Technology for MLS Cylinder Head Gaskets2005-01-17504/11/2005
The development of cylinder-head gaskets over the last ten years has mainly been characterized by adapting multi-layer metal technology to meet the highly diverse, steadily rising standards of modern high-performance engines. The modular design of the sealing system - with coating, beads and stoppers as the functional elements - allows for precise adjustments to the specific technical requirements of the engine. With new sealing and production technologies, gasket manufacturer has managed to achieve more cost-efficient solutions together with improved performance. One big step in this direction was made by developing innovative coined stoppers, the serpentine stopper for spring steel layers and the honeycomb stopper for layers made of cold rolled steel. Beside cost advantages, a wide range of additional technical benefits can be realized. With topographic stopper designs and topographic supporting elements, the gasket design can be adjusted ideally to the engine structure's stiffness. These two types of coined stoppers have been integrated in each type of multi layer steel (MLS) gasket regardless the number of layers or gasket thickness. The concept has been tested, released and is in mass production with high power gasoline and diesel engines.
Diez, Armin, Werz, Ulrich
2004 Paris Motor Show highlightsAUTONOV04_0111/1/2004
Though themes were distinctly elusive, there was a broad spectrum of technology, design, and styling on display from Europe-based manufacturers. Most international motor shows have themes. There may be a plethora of both likely and unlikely concepts, of technologies enhancing environmental responsibility, of safety systems…or performance cars. At Paris this year, though, themes were distinctly elusive. Instead, there was on display the whole glittering gamut of the international motor industry at its best, showing what it could do across a broad spectrum of technology, design, and styling, while bringing out evolutionary and revolutionary solutions to challenges real and imagined. Despite the endless pursuit of low emissions, economy, and practical, value-for-money vehicles, kilowatts still figured prominently. And glamour, that essential ingredient for success, was on almost every stand. The car, it seems, is still a long way from becoming the purely functional mechanical device that is its basis, and the words “automotive engineering” will continue to mean a great deal more than four wheels, an engine-and a hunk of metal to keep out the rain. Following are highlights of the Paris show from Europe-based automakers.
Birch, Stuart
The Development of the New Ford Heavy Duty Truck Engine, ECOTORQ2004-01-268810/26/2004
FORD OTOSAN has developed a new heavy-duty diesel engine, ECOTORQ, for the new Ford Cargo Trucks whose production started in September 2003. The engine is 7.3 liters, 6-cylinder in-line, with common rail fuel injection system and overhead camshaft design having 4 valves per cylinder. The engine meets the Euro-III exhaust emissions limits, which were in effect when it was introduced, and the engine incorporates the potential to meet Euro-IV. Modern computation and simulation methods were used and extensive experimental studies were made during the design and development stages, which helped reach the targets of compactness, modular structure, low fuel consumption, low noise level and low emissions.
San, Dogan, Guraslan, Ergun, Ergen, Omer Rustu, Kanar, Korhan
2005 Ford GT- Maintaining Your Cool at 200 MPH2004-01-12573/8/2004
An integrated engineering approach using computer modeling, laboratory and vehicle testing enabled the Ford GT engineering team to achieve supercar thermal management performance within the aggressive program timing. Theoretical and empirical test data was used during the design and development of the engine cooling system. The information was used to verify design assumptions and validate engineering efforts. This design approach allowed the team to define a system solution quickly and minimized the need for extensive vehicle level testing. The result of this approach was the development of an engine cooling system that adequately controls air, oil and coolant temperatures during all driving and environmental conditions.
Hill, Curtis M., Miller, Glenn D., Evans, Michael R., Pollock, David M.
The Status of Experimental Investigations on Low Heat Rejection Engines2004-01-14533/8/2004
Energy conservation and emissions have become of increasing concern over the past few decades. As automobiles are one of the major sources of energy consumption and urban emissions, engineers concerned are under significant pressure to improve their energy efficiency and reduce exhaust emission levels. While tremendous effort has been devoted in improving performance and reducing emissions of current engines, new technologies are also getting attention. One example is the Low Heat Rejection Engine (LHRE). A technological thrust is currently in progress to develop insulated, low heat rejection engines which exhibit higher thermal efficiency and improved exhaust emissions. The low heat rejection engine concept is not new. For the past two decades many have conducted experiments on low heat rejection engines. Although promising, the results of the experimental investigations have been somewhat mixed. Many have shown that insulation reduces heat transfer but none have shown substantial gains in efficiency, performance and emissions. Some investigators even concluded that insulation increases heat transfer and degrades the performance of the engine. This paper presents a general overview about the previous experimental research efforts into low heat rejection engine concept. This paper explains in detail the engine used, test conditions and constraints, insulation materials used, degree of insulation and results obtained by different researchers in their experimental investigation. The factors that affect thermal efficiency, other performance parameters and exhaust emissions were deduced and their influences discussed.
Jaichandar, S., Tamilporai, P.
Improving the University of Idaho Clean Snowmobile2003-32-00759/16/2003
The University of Idaho's entry into the 2001 SAE Clean Snowmobile Challenge provided proof-of-concept for a clean and quiet snowmobile using a four-stroke engine, exhaust after-treatment, and electronic fuel injection. This combination provided excellent emissions and fuel consumption performance while maintaining acceptable power. In 2002, the UI improved on this design by fine-tuning the engine, using higher efficiency components to improve power transmission, and adding sound damping to reduce noise. For 2003, the University of Idaho continued to improve on this design with a larger displacement engine, a tuned exhaust, and a new strategy on noise emissions. Results included achieving First Place overall in the competition, and five other awards. The team also began developing a direct injection two-stroke engine for competition in future years.
Bradbury, Nathan, French, Forrest, DenBraven, Karen R.
Georgia Tech's FutureTruck Split-Parallel Hybrid SUV Design2003-01-12703/3/2003
The Georgia Tech FutureTruck Team has designed a strong parallel split-hybrid powertrain for the model year 2002 Ford Explorer SUV. The modified powertrain uses a Lincoln LS 3.0L, V-6, DOHC, aluminum engine driving the rear axle. An AC-150 from AC Propulsion is coupled to the front wheels through a 3.75:1 Auburn Gear speed reducer. This split-hybrid structure fits well into the Explorer and is to manufacture. The interior cabin has been maintained in a stock configuration by carefully integrating the added instrumentation and electric drive controls into the dash and console. The toque-blending hybrid electric control is designed to be charge sustaining such that the refueling procedures match those of the stock vehicle. When fully operational, this powertrain is expected to yield a net 25% increase in fuel efficiency while lowering emissions without any sacrifice in customer acceptability.
Biggers, C., Mandeltort, P., McClearen, J., Meisel, J., Parsons, J., Renteria, V., Riley, C.
Summary of Results of Development and Validation of Hot Honing System to Provide Improved Engine Performance2002-01-329912/2/2002
Operating cylinder bore geometry and finish have been identified by numerous investigators over the years as having the capability to modify oil consumption, blowby, wear, and engine friction. It has also been recognized that cylinder bores, even though machined and honed to a round state at the time the block is produced, change shape when cylinder heads are installed and when the engine reaches normal operating temperatures. The concept of heating the block with a simulated head plate and then honing the cylinder bore to achieve a round bore has been evaluated by race engine builders over the years. A number of Formula One engine builders have utilized cylinder bore geometries which were developed while the bores were honed with the cylinder liner installed in a heated block with a heated hone plate. Review of the published literature and discussions with major race engine builders have indicated that minimal organized information on hot honing techniques, procedures, and associated equipment is available. This paper outlines and summarizes procedures followed, data accumulated, and conclusions developed in this study. Utilizing the procedures outlined, it appears that 1-2% improvement in horsepower can be achieved with a corresponding reduction in power loss in the cylinder kit system in an otherwise well-developed high-performance engine.
McCormick, Harold, Meara, Tim
A Clean, Quiet, Environmentally Friendly Snowmobile2002-01-276310/21/2002
In an attempt to reach a compromise between the views of environmentalists and snowmobile enthusiasts, the University of Wisconsin-Madison Clean Snowmobile Team set out to design a machine that maintains performance while decreasing air and noise pollution. After careful consideration of all possible design avenues, the decision was made to select a four-stroke power plant. In order to optimize the engine's efficiency, an engine control unit was chosen that was both capable and affordable. Engine modifications were made to allow the snowmobile's stock transmission to be used. Alterations were also made to intake, exhaust, and cooling systems to allow the engine to fit comfortably under the snowmobile's stock hood. Modifications were made to the snowmobile's chassis to accommodate the additional mass associated with the four-stroke engine. The final product is a snowmobile that minimizes environmental impact but still has the appearance and performance necessary to satisfy consumers.
Marshaus, Julie G., Allen, Jake, Bauer, Tony, Martinek, Chris, Martinek, Matt, Boyarski, Nick, Mauermann, Fred, Trettin, David, Bower, Glenn R.
A New Evaluation Method for the Measurement of Internal Corrosion Resistance in Braze Clad Alloys2002-01-03883/4/2002
Historically, the development of brazing alloys for heat exchangers has focused on improving mechanical properties, improving external corrosion resistance and retaining good brazeability. Recently, the interest has been in the measurement of internal corrosion resistance and the development of aluminum alloys that will provide good internal corrosion resistance. Previously, testing to determine the internal corrosion resistance was performed on full size units. Herein is a description of an internal corrosion test loop, which has been designed and manufactured for testing internal corrosion resistance on small coupons of material. The test results for the coupons have been compared to those of a full size radiator that was exposed simultaneously with the coupons in the same corrosion test loop. The similarity between the results validates the ability of the system to test sheet specimens prior to production trials.
Johnson, Greg, Connor, Zayna M., Stauver, H. L., Murty, G. S.
Phasing Strategy for an Engine with Twin Variable Cam Timing2002-01-11013/4/2002
Twin camshaft phasing was applied to a 1.6l 4-cylinder 16-valve DOHC engine. Both camshafts - intake and exhaust - were equipped with continuously adjustable cam phasing units. Different operating strategies were compared with regard to mechanical feasibility, thermodynamics and calibration. Attractive part load fuel economy was achieved with two different phasing strategies. With regard to full load and idle a preferred twin camshaft phasing strategy was determined. It was found favorable to shift the intake camshaft largely towards ‘advance’, and the exhaust camshaft towards ‘retard’. Maximum fuel economy improvement was 8% at 2500 rpm and 3 bar mean effective pressure. In the European drive cycle 5 % fuel economy improvement was obtained. To achieve superior performance it is mandatory to combine twin camshaft phasing with an appropriate exhaust system and optimized cam events. The best exhaust system was found to be a 4-2-1 manifold with 2 closed coupled catalysts in the manifold secondaries. With such an exhaust system, a tuned intake manifold and optimized cam events, a mean effective pressure of 12 bar was demonstrated between 2000 rpm and 4500 rpm. Compared with the base engine the maximum torque increase at 2000 rpm amounted to 15 %. The average torque increase was 10 %. The described phasing strategy led to a 50 % reduction in NOx feedgas emissions in the European drive cycle. This reduction, along with the homogenous, stoichiometric operation enables the twin camshaft phasing technology to fulfill the tightest emission regulations with customary fuel quality and standard aftertreatment technology.
Kramer, Ulrich, Phlips, Patrick
Cleaner and quieter snowmobilesOFHJUN01_016/1/2001
The University at Buffalo's entry into the Clean Snowmobile Challenge led to modifications of engine, exhaust, body, and electronics to achieve a snowmobile with both lower noise and emissions. The snowmobile industry has been challenged to reduce the amount of exhaust emissions and noise output associated with two-stroke engines to allow for the continued use of snowmobiles in environmentally sensitive areas without sacrificing performance. Given these considerations, members of the University at Buffalo SAE Clean Snowmobile Team improved the noise, fuel economy, cost, and durability of a snowmobile suitable for an average consumer. The task was accomplished via the selection of a cleaner and more reliable four-stroke engine-a Polaris Sportsman 500-as the powerplant. The engine is liquid cooled and electronically fuel injected using an engine-management system that is currently in production. A catalytic converter was employed to help further reduce emissions.
Metallurgical Aspects of Aluminum Lost Foam Automotive Castings2001-01-04123/5/2001
Metallurgical aspects of the lost foam aluminum casting process used for production of 4-cylinder engine blocks and cylinder heads are presented. Results represent a high-volume lost foam foundry producing a common alloy, AA 319.0-T5, for all components. The influence of proper chemistry selection, degassing of liquid aluminum and heat treatment on casting microstructure and material properties are reviewed. The material properties include hardness, tensile strength, elongation, low and high cycle fatigue strength.
Genualdi, Andrew J.
A Low-cost Modular Small Engine System Utilizing Extruded Aluminum2001-01-12083/5/2001
The use of modularized aluminum extrusions for the block, crankcase and head in small engine systems allows a range of engines to be mass produced without resort to casting for the stationary components. The use of modern accurately dimensioned extrusions greatly reduces the machining required. The versatility and strength of extruded aluminum alloys enables the elimination of load bearing threads and most other finish machining, thus significantly reducing the labor costs of manufacture. A range of strokes and hence of different capacity engines can be produced from a single extrusion form. For extended life, bores can be coated with a variety of finishes, including simple anodizing. Extrusion technology allows cost-effective engines to be manufactured with a significantly lower investment than with other technologies.
Savage, Peter, Bydder, Evan, Witehira, Peter
An ADI Crankshaft Designed for High Performance in TVR's Tuscan Speed Six Sports Car2001-01-04083/5/2001
The TVR Tuscan Speed Six, (produced by TVR Engineering in Blackpool, England) is a high performance automobile, by any measure. This low volume sports car weighs 1,100 kg (2,420 lbs) and is powered by a 4-litre in-line six-cylinder engine that develops over 350 bhp and 310 ft-lb of torque. TVR Engineering selected an Austempered Ductile Iron (ADI) crankshaft for its combination of low cost, low weight and high torsional strength. Not since Ford dabbled with ADI in its race cars in the 1980's has a manufacturer chosen ADI for its crankshafts. Although virtually all the major automotive producers and the Motor Industries Research Association (MIRA) have investigated ADI for use in crankshafts, this is the only known production application of ADI crankshafts in automobiles. ADI presents a useful set of properties for the design engineer. With ever increasing specific power requirements for new engine designs, new material/process combinations for engine components are being explored. This paper will discuss the properties of ADI, the reason for its selection for this crankshaft, and its suitability for this application.
Brandenberg, Kristin R., Ravenscroft, John, Rimmer, Arron, Hayrynen, Kathy L.
Design of a Restricted Induction System for a High Speed Four Cylinder Engine2000-01-30908/21/2000
Members of the 2000 Lawrence Technological University Formula SAE (FSAE) team are currently developing a new prototype intake system to be used on the new Formula vehicle. The vehicle will be using a 600 cubic centimeter four stroke Honda motorcycle engine. As required by the rules of FSAE, the intake system must be restricted to limit the engines potential to produce power. Development work was done using a flow test bench and engine dynamometer on all available previous designs. The two best previous designs were then compared to help determine the optimized dimensions and geometry for the new design. After the new prototype model was finished it was tested to validate theoretical calculations and overall performance.
Jawad, Badih A., DeGain, Michael D., Young, Anthony P.
Extended Life Carboxylate Coolant Compatibility with Other Coolant Technologies - Examining the Data2000-01-19776/19/2000
Previous studies examined the effect of low levels of silicate (∼<75ppm Si) on hot aluminum corrosion protection. The corrosion protection provided by different coolant technologies was evaluated at different silicate levels. The results indicated that small amounts of silicate have a negative effect on the corrosion protection of aluminum. This work will examine these results and evaluate the effectiveness of different laboratory tests for determining coolant “compatibility.” Results will be examined from several bench and fleet tests showing the effect of coolant mixing on the corrosion rates in various environments. The bench test results will include laboratory glassware and dynamic tests that have been used historically to evaluate coolant compatibility. Differences between the test methods will also be evaluated to determine the relevance of each test procedure in light of the fleet observations.
Fritz, Paul O., Bartley, Leonard, Maes, Jean-Pierre, Van de Ven, Paul
Friction Reduction - the Engine's Mechanical Contribution to Saving Fuel2000-05-01606/12/2000
Over the last few years, engine development has succeeded in reducing friction by up to 30 %. This corresponds to a reduction of fuel consumption in urban traffic of around 10 %, thus, making friction reduction - aside from the introduction of Otto DI engine and the transition from IDI to DI Diesel engines - an effective measure to reduce fuel consumption. Investigations of engines and engine components show that even today's “Best in Class” engines still harbor a reduction potential of least 20 %. Possible ways to realize this potential lie in: Adapted dimensioning of the friction relevant engine parameters Lightweight design of dynamic components Optimized layout of the timing drive (especially in valve train designs with roller followers and chain drives) Optimization of the piston group (up to 50 % of the parasitic losses can occur here) The investigations are based on detailed friction measurements of over 100 sample engines and their components. The analysis of the measured data, together with more in-depth measurements using special measurement techniques give insight into current trends and directions for new designs. With the help of benchmarking and simulation programs, the influence of individual design parameters on the friction behavior and variants can be found. This paper is meant to highlight the often hidden role of engine mechanics in the development of fuel consumption favorable engines and compare it to the development steps of SI and Diesel engine procedures.
Schwaderlapp, Markus, Koch, Dr.-Ing. Franz, Dohmen, Dipl.-Ing. Jürgen
Development of ultra-high-speed machining center using tilt-positioning system2000-05-01836/12/2000
The mainstream solution in the machining line for aluminum engine components; i.e., cylinder blocks and cylinder heads, has been provided by a transfer line featuring a multi-spindle machining device. In spite of the advantages it can offer, the conventional system is found less appropriate for meeting recent demands. These demands are; minimized investment for adapting the system to new production, and enhanced flexibility to cope with more diversified manufacturing demands. A possible answer would be machinery that simultaneously achieves production efficiency similar to that of the multi- spindle machine and the flexibility of the NC machine. To achieve this goal, the "HVT-6000," an ultra-high-speed machining center featuring a tilt- positioning mechanism using direct drive (DD) motors, was developed.
Suzuki, Yoshihiko, Kousaka, Tomomi, Yoshida, Takashi
Rationale for Technology Selections in GM's PNGV Precept Concept Car Based on Systems Analysis2000-01-15674/2/2000
The CY2000 cornerstone goal of the Partnership for a New Generation of Vehicles (PNGV) is the demonstration in CY 2000 of a 5-passenger vehicle with fuel economy of up 80 mpg (3 l/100km). As a PNGV partner, GM will demonstrate a technology-demonstration concept vehicle, the Precept, having a lightweight aluminum-intensive body, hybrid-electric propulsion system and a portfolio of efficient vehicle technologies. This paper describes: 1) the strategy for the vehicle design including mass requirements, 2) the selection of dual axle application of regenerative braking and electric traction, and 3) the complementary perspective on energy management strategy. This paper outlines information developed through systems analysis that drove technology selections. The systems analyses relied on vehicle simulation models to estimate fuel economy associated with technology selections. Modeling analyses included consideration of both federal test requirements and more severe driving situations. The vehicle design accommodates default Tier 2 emission requirements. New Tier 2 requirements proposed by EPA in 1999 necessitate additional development.
Sloane, Christine S., Zemke, Bruce E., Claypole, George M., Laws, Larry D.
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