Browse Topic: Pressure

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Experimental Investigation of n-C7H16/Ethanol Blended Fuels on Auto-ignition and Flame Propagation in High Temperature/Pressure Constant-Volume Combustion Vessel2024-32-005004/18/2025
This study aims to investigate the effect of ethanol blends on flame propagation and auto-ignition under high pressure and high temperature conditions. Experimental investigations are conducted using n-C7H16 / ethanol blends at various blending ratios (0, 5, 10, 20, 40, 70, and 100 vol%). The blends are premixed with air at stoichiometric ratios and ignited centrally in a cylindrical constant-volume combustion chamber (20-mm inner diameter, 80-mm long) under elevated temperature (500 K) and pressure (1.0 MPa) conditions. The results show that auto-ignition occurs at an ethanol blend ratio of 10% or less and ceases above 20%. Increasing the ethanol blend to 70% results in a slight change in flame propagation speed, with a noticeable delay at 100%. The pressure measurements show a peak of about 5.6 MPa at a blend ratio of 5%, which gradually decreases with increasing ratios. High-pass filtering reveals the maximum pressure fluctuation amplitude at the 5% blend ratio, indicating increased
Tateishi, Tokua, Yamaguchi, Riki, Shimokuri, Daisuke, Terashima, Hiroshi, Hara, Takaya, Honda, Yuya, Kawano, Michiharu
Detailed Approach for Pre-Chamber Heat Release Analysis for the HSASI Pre-Chamber Spark Plug Using a Pressure Sensor Glow Plug2024-32-006304/18/2025
The hot surface-assisted spark ignition (HSASI) pre-chamber spark plug, which was developed at the Karlsruhe University of Applied Sciences, increases the dilution limit with excess air and the tolerance to residual gas in the pre-chamber compared to a conventional passive pre-chamber spark plug. In this study, the conventional glow plug which is integrated in the pre-chamber of the HSASI pre-chamber spark plug was replaced by a pressure sensor glow plug (PSG) from BERU. This allows for a detailed combustion analysis in the pre-chamber. The signal of the PSG was validated with a piezoelectric cylinder pressure sensor and a method to analyse the pre-chamber heat release was introduced. Experimental investigations were carried out on a single-cylinder gasoline engine. A series of operating points diluted with excess air and a variation in load were conducted. The gas flow rate through the orifices of the pre-chamber was calculated from the pressure difference between the pre-chamber and
Holzberger, Sascha, Kettner, Maurice, Kirchberger, Roland
Study on the Optimal Pre-Chamber Geometry for Active Pre-Chamber Gas Engines2024-32-002304/18/2025
In a pre-chamber engine, fuel in the main-chamber is ignited and combusted by the combustion gas injected from the pre-chamber. Therefore, further fuel dilution is possible and thermal efficiency can be also improved. However, adding a pre-chamber to an engine increases the number of design parameters which have a significant impact on the main combustion and the exhaust gas. Then, in this study, the optimum geometry of the pre-chamber in an active pre-chamber gas engine was investigated. The considered parameters were the volume of pre-chamber, the diameter of a nozzle hole, and the number of nozzle holes. 18 types of pre-chambers with different geometries were prepared. Using these pre-chambers, engine experiments under steady conditions were conducted while changing the conditions such as engine speeds, mean indicated pressure and air excess ratio. Based on the experimental data, neural network models were constructed that predict thermal efficiency, NOx and CO emissions from the
Yasuda, Kotaro, Yamasaki, Yudai, Sako, Takahiro, Takashima, Yoshitane, Suzuki, Kenta
SAE TOMORROW TODAY BRIEFS: How "Talking" Cyber Tires Make Driving Safer1347909/23/2024
What if your tires could talk? And your car would listen? Pirelli's new Cyber Tyres use Bluetooth-connected sensors to communicate directly with the car, using data to make adjustments in real time. This information - including temperature and pressure - is vital when it comes to increasing safety. To learn more, Roberto Baldwin, Sustainability Editor, SAE Sustainable Mobility Solutions, sat down with Pierangelo Misani, Global Head of R&D for Pirelli, to discuss how this game-changing technology and the company's partnership with Bosch is shifting connected tire technology from reactive to proactive. For more information on the evolution of sustainability, head on over to sustainablecareers.sae.org. There, you can check out our interview with the Polestar CEO about the future of charging.
Hineman, Marcie
SDPF Application DOE For BS6 RDE/OBD2 using MATLAB/SGB/ETB/CDT2024-26-016101/16/2024
To meet future emission levels, the industry is trying to reduce tailpipe emissions by both, engine measures and the development of novel catalytic emission control concepts. The present study will focus on the close coupled SCR on Filter commonly known as SDPF which is a main pathway to reduce NOx along with Particulate mass and number for light duty passenger cars and sport utility vehicles for BS 6 RDE/OBD 2 and future legislation like BS-7. SDPF is a challenging technology as it is critical component in exhaust after treatment system involving in NOx and PM/PN reductions hence careful optimization of this technology is necessary in terms of Space velocity requirements, Temperature profile wrt to NOx conversion, Raw NOx concentration, Particulate mass and Ash holding capacities, NH3 storage requirements, back pressure and so on. With BS6 RDE having extremely challenging CF for NOx equals to 1,43, the SDPF design & optimization is high on importance and to demonstrate the success of
Singh, Shephali, Patil, Sandip, Maynal, Rajesh A., Maske, Vidyasagar, Seyler, Michael, Subramanian, Senthilnathan, Deshpande, P V, Luquman, Shahid
Soot sensor elimination with DPF substrate failure monitoring.2024-26-015301/16/2024
The automobile industry is going through one of the most challenging times, with increased competition in the market which is enforcing competitive prices of the products along with meeting the stringent emission norms. One such requirement for BS6 phase 2 emission norms is the inclusion of PM (Soot) sensor in diesel passenger cars. PM sensor detects soot leakage in case of DPF substrate failure. There is a cost factor along with extensive calibration efforts which are needed to ensure sensor works flawlessly. This paper deals with the development of an algorithm with which robust detection of DPF substrate failure is achieved. In order to achieve this, a thermodynamic model of DPF substrate was created using empirical relations between parameters like exhaust flow rate, exhaust gas temperature and soot mass content. The modeling was done in both empty (no soot) and filled (threshold soot content) substrate conditions. There were two methodologies, namely integration method and
Jain, Praveer Kirtimohan, Yadav, Omkar, Chendil, Chellapandi
Improving Dynamic Response of PEMFC Anode Pressure in Droped Load Scenarios through Split Range Control2023-01-702610/30/2023
The dynamic response of proton exchange membrane (PEM) fuel cells’ anode pressure and the pressure difference between the cathode and anode significantly influence the performance and durability of fuel cells. To address the slow dynamic response of the anode pressure during rapid load drops, this study proposes a split range control strategy by introducing the hydrogen purge valve into the anode pressure control. By rational planning the split range block, the hydrogen purge valve is opened at appropriate times during load drops. To validate the effectiveness of the split range control, simulations are conducted under load drop conditions using an 80 kW fuel cell hydrogen and air supply subsystem model. The simulation results demonstrate that the split range control reduces the setting time of the anode pressure during load drops by half, with the most significant improvement observed at 67% load to idle condition, where the setting time is reduced from 2.6 s to 1.1 s. Furthermore
Zhang, Junyu, Chen, Fengxiang, Pei, Fenglai, Li, Tao, Xu, Shuo
Characterize the Sound Field Generated from a Vehicle Horn by Pellicular Analysis2025-01-005805/05/2023
To predict the sound field produced by a vehicle horn requires a good source representation of it in the full vehicle model. This paper investigates the characterization of a physical vehicle horn by an inverse method called pellicular analysis. To implement this method, firstly an acoustic testing is performed to measure the sound pressure radiated from the horn at a certain number of microphone locations in a free field environment. Based on the geometry of a virtual horn, the locations of each microphone and measured sound pressure data, pellicular analysis is adopted to recover a set of vibration pattern of the virtual horn. The virtual horn and the recovered vibration information are then incorporated in a full vehicle numerical model to simulate its exterior sound field. The validity of this approach is confirmed by comparing the prediction for a horn in a production vehicle to the corresponding physical test which is required to meet the Brazilian regulation CONTRAN 764/2018.
Yang, Wenlong, MELO, ANDRE
Tonal noise investigation of automotive HVAC systems : a hybrid method2025-01-002705/05/2023
There is no need to recall how the electrification trend of transport facilities has tightened the requirements around acoustic comfort. Within the automotive industry, these targets are more challenging for Heating, Ventilation and Air Conditioning systems for which passengers are in the foreground of noise emissions. The complexity of the requirements and specifications set by car manufacturers and suppliers stems from a dual aspect. First is quantitative based on the sound pressure level, whether it's the overall level or 1/3 octave band spectra. The second is purely subjective based on the perceived noise quality by stakeholders and final customers worldwide. During development phases, low frequency tone noises are frequently encountered on these systems which might induce discomfort to the passengers. The experimental investigations usually point to an aerodynamic origin, which prompted this research activity. The purpose of this work is to analyze and understand the mechanism of
Bennouna, Saad, Alaoui, Mohamed
Experimental Investigation into Modulated Aeroacoustic Cabin Noise arising from Unsteady Flow Conditions2025-01-002905/05/2023
The unsteady wind conditions experienced by a vehicle whilst driving on the road are different to those typically experienced in the steady-flow wind tunnel development environment, due to turbulence in the natural wind, moving through the unsteady wakes of other road vehicles and travelling through the stationary wakes generated by roadside obstacles. This paper presents the use of experimental approach using an SUV-shaped vehicle to assess the effect of unsteady wind on the modulated noise performance, commonly used to evaluate unsteady wind noise characteristics. The approach is extended to assess the pressure distribution on the front side glass of the vehicle, caused by the aerodynamic interactions of the turbulent inflow, to provide insight into the noise generation mechanisms and differences in behaviour between the two environments. The vehicle response to unsteady wind conditions was assessed using two approaches: a dynamic upstream unsteady flow the using active side wind
Jamaluddin, Nur Syafiqah, Oettle, Nicholas, Staron, Domenic
A Methodology to Design the Flow Field of PEM Fuel Cells2023-01-049504/11/2023
Proton Exchange Fuel Cells (PEMFCs) are considered one of the most prominent technologies to decarbonize the transportation sector, with emphasis on long-haul/long-range trucks, off-highway, maritime and railway. The flow field of reactants is dictated by the layout of machined channels in the bipolar plates, and several established designs (e.g., parallel channels, single/multi-pass serpentine) coexist both in research and industry. In this context, the flow behavior at cathode embodies multiple complexities, namely an accurate control of the inlet/outlet humidity for optimal membrane hydration, pressure losses, water removal at high current density, and the limitation of laminar regime. However, a robust methodology is missing to compare and quantify such aspects among the candidate designs, resulting in a variety of configurations in use with no justification of the specific choice. This contrasts with the large operational differences, especially regarding the pressure loss
Corda, Giuseppe, Cucurachi, Antonio, Diana, Martino, Fontanesi, Stefano, D'Adamo, Alessandro
Ultrathin Pressure Sensor Attaches to SkinTBMG-4649209/01/2022
Researchers have developed an ultrathin pressure sensor that can be attached directly to the skin to measure how fingers interact with objects to produce useful data for medical and technological applications. The sensor has minimal effect on the users’ sensitivity and ability to grip objects and it is resistant to disruption from rubbing.
An Effective Design of Micro Tesla Valve as a Passive Mixer in Microfluidics Channels 2022-26-117805/26/2022
Mixing fluids is one of the major challenges in microfluidics. Normally, the mixing process is done by diffusion rather than turbulence, which makes it very slow due to low Reynolds number (Re) flow in the range of 0.1 to1. Owing to this behaviour, ineffective mixing occurs when two miscible liquids are mixed purely by diffusion which requires longer striation lengths and therefore longer microfluidic channels along with lengthy mixing time. Homogeneous mixing of solute and solvent is important for providing consistent chemical and biological reactions in µTAS.In this study, we develop a passive mixer that provides efficient mixing using micro tesla valves which allows the flow of liquids in the forward and reverse directions to analyse the formed vortices, turbulent intense areas, Reynolds number, and pressure using Ansys fluent workbench. An optimum design has been arrived by varying the number of cells from 1 to 5 in series and realization is done by excimer laser micromachining.
Singh, Deepak, Sankar PhD, Ravi
Effect of low viscosity oil and bearings design on oil pressure performance across engine crank train system 2022-01-076703/29/2022
In current market scenario Reliability & Durability of components as became prime focus, with the advent of BS VI emission norm there is tremendous increase in peak firing pressure due to high pressure common rail system and various emission solutions. Crank train system is getting subjected to a never before forces & loading due to emission & performance requirement. For achieving the competitive reliability & durability of main moving parts oil pressure plays a most vital role. In this study the performance optimization of oil pressure has been carried out by experimenting with oil grades & bearing designs. This study comprises of selection of oil & bearing, simulation and finally proto development & verification. Further, the result were compared and best solution recommended.
Gavade, Sujit Vithoba, Gangurde, Prashant, Bhargava, Aashish, Pawar, Satish, Deshmukh, Chandrakant, Mishra, Abhishek
Characterizing shock waves induced by phase change of superheated liquid jets 2022-01-059403/29/2022
The under-expanded nature of flash-boiling spray was considered an important cause of spray collapse via some numerical investigation. However, due to the high optical thickness, the under-expanded nature in flash-boiling jet was difficult to observed by optical diagnosis. The main objective of this study is to prove the existence of under-expanded nature in the gasoline-like fuel (n-hexane) flash-boiling jet under the GDI engine condition, and further reveal the significant influence factors. The experimental examination was carried in a constant volume vessel with ambient pressure ranging from 0.1 bar to 1.0 bar and fuel temperatures from 30℃ to 170℃. In order to capture the flow details in the jet, a high-brightness light source was used in the optical imaging. The shock structure of under-expanded nature was observed in close nozzle region under those conditions above 130℃, and the shock structure was in good agreement with the previous simulation results under the same conditions
Li, Yanfei, Zhang, Jingyu, Ma, Xiao, Shuai, Shijin
Ultimate Breakage Load Calculation Method of Cold Gas Inflator Burst Disk2022-01-093803/29/2022
For cold gas Inflator, high refinement of ultimate load forecast is one key of Inflator development. At beginning, two methods based on implicit algorithm, Zero Curvature method and RIKS method were used for burst disk hydro-burst test ultimate pressure load calculation. After considering the effect of bursting disk stamping process, comparing with results of real test, the refinement of the two methods were above 97% both. Studying the corresponding relations between displacement and stress matrix of the center point of burst disk by RISK method. It was found that under ultimate load, the third principal stress vs. displacement curve of the central node shown extreme point, and load step of the point was corresponding the one of maximum pressure load. This shown that after reaching the ultimate load, the center of the bursting disc lost stability in the direction of thickness. Based on the status of stress matrix analysis results of RIKS method, and for solving the nonlinear contact
Shan, Jinhui, Wang, Cheng
Numerical Investigation on the Internal Flow Field of Electronic Expansion Valve as the Throttle Element2022-01-037803/29/2022
As one of the key components of the heat pump system, the electronic expansion valve mainly plays the role of throttling and reducing pressure in the heat pump system. Firstly, a three-dimensional fluid model is established. The grid is divided and the grid independence is verified. Then, the internal flow field of the electronic expansion valve is numerically simulated based on the fluent software, and the pressure field, velocity field and flow rate changes are analyzed. The flow characteristics of the valve are theoretically analyzed according to the principle of the fluid passing through the orifice. Secondly, the flow characteristics of the valve are simulated, and the theoretical values, CFD simulation results and experimental values are compared to verify the correctness of the established three-dimensional fluid model. Then the influence of geometric parameters such as the diameter and cone angle of the spool on the flow characteristics is studied. The steady-state hydraulic
Liang, Gaoshuai, Li, Liping, Shangguan, Wen-Bin
Modelling Transient Control of a Turbogenerator on a Drive Cycle2022-01-049503/29/2022
GTDI engines are becoming more efficient, whether individually or part of a HEV (Hybrid Electric Vehicle) powertrain. For the latter, this efficiency manifests itself as increase in zero emissions vehicle mileage. An ideal device for energy recovery is a turbogenerator (TG), and, when placed downstream the conventional turbine it has minimal impact on catalyst light-off and can be used as a bolt-on aftermarket device. A Ricardo WAVE model of a representative GTDI engine was adapted to include a TG (Turbogenerator) and TBV (Turbine Bypass Valve) with the TG in a mechanical turbocompounding configuration, calibrated using steady state mapping data. This was integrated into a co-simulation environment with a SISO (Single-Input, Single-Output) dynamic controller developed in SIMULINK for the actuator control (with BMEP, manifold air pressure and TG pressure ratio as the controlled variables). Transient verification with WAVE-RT was conducted on WLTP and NEDC drive cycles, estimating
Petrovich, Simon, Ebrahimi, Kambiz, Mason, Byron, Watson, Andrew
METHODOLOGICAL APPROACHES TO CONTROL HC AND CO EMISSIONS DURING COLD CONDITIONS2022-01-054403/29/2022
Diesel Engines are known for its low fuel consumption and at the same time for higher emission formation (NOx, HC, CO and SOOT). Meeting Emission and CO2 targets simultaneously become tough challenge for the Combustion Engineer. HCCI and PCCI combustion concepts allow the reduction of NOx and Soot simultaneously to very low levels with help of Exhaust gas re-circulation (EGR) while maintaining the CO2 emissions advantage of a diesel Engine But due to the low Combustion temperatures, HC and CO will rise drastically, especially when the catalyst bed temperature is not enough to reach light-off temperature to initiate the after-treatment process. This condition will become serve in Lower Engine temperatures (Cold condition) due to the heterogeneous nature of Diesel Combustion and also affects the BSFC of an Engine. At first multiple injection strategies (Pilot quantity and Pilot separation) has been studied to control both HC and CO by increasing the global combustion temperature. In
Mutta, Surendranath
Evaluation of the Effect of Ambient Conditions on the Fuel Consumption of Commercial Vehicles2022-01-064203/29/2022
The goal of this study was to evaluate the effect of environmental conditions, and particular of ambient temperature, on fuel efficiency. Data from various and extensive operational testing were analyzed, such as tests conducted with four groups of medium and heavy-duty vehicles, involved in regional transport, local transport, pick-up and delivery, and urban transport (school bus). The tests were conducted over 5 months of warm season followed by four months of cold season. Other operational testing was conducted over one year in two different geographic and climatic regions in Canada. Data from extensive track testing conducted based on the SAE J 1321 Fuel Consumption Test Procedure-Type II, with various vehicles in different test condition, from spring to winter, was also analyzed. In this type of tests, a control vehicle is used for the base trial, as well as the final trial. As there is no change on the control vehicle, only the environmental conditions impact the fuel consumption
Surcel, Marius-Dorin
Sensor-controlled Friction Materials based on Liquid Friction Compounds, Chip-in-Pad Concept2021-01-129610/11/2021
In this paper, the concept of integrating thin-film piezo transducers into friction pads by using a liquid friction material compound (LIQFRIC® HP), which is capable of completely embedding the sensor surface and allowing for the force transfer due to a direct contact between sensor and friction material, is explained. The low thickness of the sensor allows for an excellent ratio of sensor volume / friction volume in the pad. The piezo transducer, besides being able to detect positive and negative pressure changes, can also be used via its EMI capability to allow measurements of changes in the shape (and therefore thickness) of the pad during and after testing. Measuring the pressure distribution, the wear and possible defect situations of the pad potentially opens up new means of friction pad- and brake operations or developments.
Milczarek, Roman Paul
A Study of Emission Durability and Ash Accumulation of “Advanced Three-Way Catalyst Integrated on Gasoline Particulate Filter” for BS6 (Stage2) Applications2021-26-018209/22/2021
India BS6 Stage2 (2023) regulations demands all Gasoline direct injection (GDI) vehicles to meet particulate number emissions (PN) below 6x10+11# per km. Gasoline particulate filters (GPF) are a proven technology and enable high PN filtration efficiencies throughout the entire vehicle lifetime. One challenge for GPF applications could be the changing emission performance characteristics as a function of mileage due to collected ash and/or soot deposits with implications on back pressure losses and well due to aging of active catalytic components like PGM and Washcoat. The main objective of this technical contribution is to study the above-mentioned challenges while applying Indian driving conditions and typical Indian climate and other ambient conditions. The substrate technology selected for this study is a high porosity GPF designed to enable the integration of a Three-Way functionality into the GPF, commonly described as coated GPF. In this study, the entire Three-Way Catalyst (TWC
Rose, Dominik, Tao, Tinghong, Kataria, Rohit, Boger, Thorsten, Kuehn, Nikolas, Kunert, Susanne, Richter, Joerg Michael, Magar, Avinash
Coastdown Road Load Coefficients of Passenger Vehicles – Variation Analysis and its Correlation with Temperature2021-26-048709/22/2021
Road Load parameters (rolling resistance & aerodynamic drag) of a vehicle have strong impact on overall Vehicle Emissions & Fuel Economy. The road load coefficients are simulated on chassis dynamometer to carryout emission & fuel economy measurement and are hence required to be found beforehand. A realistic measure of road load parameters can be obtained by conducting a coastdown test. Coastdown test results are hugely impacted by various environmental parameters like ambient temperature, atmospheric pressure, wind speed etc. Though performed in standard boundary conditions, results of multiple tests performed on a vehicle vary from one another due to variations in the mentioned environmental parameters over & above standard test to test variation. This paper aims at studying the variation in test results due to ambient temperature as one of the parameters responsible. For this study, road load coefficients from more than 100 coastdown tests conducted on oval test track for almost 30
Kuhar, Saurabhh, Pattalwar, Ashutosh, Gupta, Parveen
Spatial Correlation of Turbulent Flow Pressure Fluctuations Downstream of an Obstruction2021-01-104908/31/2021
The structural excitation by turbulent flow pressure fluctuations continues to be an important part of vehicle NVH analysis and design. Much of the analytical work on turbulent flow has been limited to flow over smooth, flat surfaces. Measurements and CFD analyses show a significantly different pressure spectrum for flows over an obstruction. The coupling of the turbulent pressure excitation to the structural vibration and transmitted sound depends on the spatial matching between the source and response fields. This paper develops an analytical model for the spatial correlation of turbulent flow pressure fluctuations downstream of an obstruction. Such a model is useful in the early design stage of a vehicle and is compatible with SEA models of the fluid structure interaction.
DeJong, Richard, Tubergen, Renard, Willson, Abigail
Minimum Standard for Portable Gaseous, Oxygen EquipmentAS1046C (Historical)08/11/2021
This standard is intended to apply to portable compressed gaseous oxygen equipment. When properly configured, this equipment is used either for the administration of supplemental oxygen, first aid oxygen or smoke protection to one or more occupants of either private or commercial transport aircraft. This standard is applicable to the following types of portable oxygen equipment: a Continuous flow 1 Pre-set 2 Adjustable 3 Automatic b Demand flow 1 Straight-demand 2 Diluter-demand 3 Pressure-demand c Combination continuous flow and demand flow.
A-10 Aircraft Oxygen Equipment Committee
Basic Aircraft Oxygen Systems DesignAIR825/14 (Current)08/11/2021
This slash document collects general reference material related to gaseous oxygen system flow requirements and sizing calculations. This document will assist oxygen system equipment designers and operators to establish systems and equipment requirements. The document consists of charts, tables, system schematics, system requirements, and sample calculations for system sizing.
A-10 Aircraft Oxygen Equipment Committee
Development of On-Board NH 3 and N 2 O Analyzer Utilizing Mid-Infrared Laser Absorption Spectroscopy2021-01-061004/06/2021
The authors present a portable NH3 and N2O analyzer utilizing mid-infrared laser absorption spectroscopy for on-board emission measurements. The developed analyzer employs a newly developed absorption spectroscopy named “infrared laser absorption modulation”, hereinafter referred to as IRLAM, for the signal acquisition and concentration determination. Because of IRLAM’s simple and robust signal processing scheme, a highly sensitive, selective and robust measurement system can be realized within a compact size. The following performance metrics of the new analyzer are presented: linearity, detection limit, response time and zero/span drift. Notably, the detection limit (defined as 2σ of the zero signal) of ≤ 0.1 ppm is achieved in both NH3 and N2O measurements. The influence of vibration, and changes in environment conditions such as ambient temperature and atmospheric pressure, are also tested. The effect of random vibrations had little observable impact on the measurement noise level
Onishi, Yusuke, Hamauchi, Shota, Shibuya, Kyoji, McWilliams-Ward, Keegan, Akita, Masanobu, Tsurumi, Kazuya
Condensation of Real-World Drive Cycle into Synthetic Drive Cycle - An Innovative Method to Predict Real Driving Emissions2021-01-060204/06/2021
The stringent emission regulations have put enormous pressure on auto manufacturers to develop vehicles with the required conformity factor (CF) on real driving emissions (RDE). However, evaluation of CF on multiple and varying real-world cycles by portable emission measurement system (PEMS) is extremely tedious and expensive. In the present work, a unique methodology is developed to condense any real-world drive cycle into a synthetic drive cycle with a reduced duration that can still match the essential driving characteristics of the real-world cycle. The principal parameters such as average velocity, gear utilization, acceleration, deceleration, cruise duration, engine idling duration, exhaust gas temperature, etc. are collected during the real-world cycle. An innovative algorithm called Real World Cycle Condenser (RWC2) is used to condense the real-world cycle into a synthetic drive cycle. The algorithm is designed to match the principal parameters between the real-world cycle and
RT, Sangeetha, Bose, Anshuman, Ibrahim, Mohamed
Accurate Pressure Control Based on Driver Braking Intention Identification for a Novel Integrated Braking System2021-01-010004/06/2021
With the development of intelligent and electric vehicles, higher requirements are put forward for the active braking and regenerative braking ability of the braking system. The traditional braking system equipped with vacuum booster has difficulty meeting the demand, therefore it has gradually been replaced by the integrated braking system. In this paper, a novel Integrated Braking System (IBS) is presented, which mainly contains a pedal feel simulator, a permanent magnet synchronous motor (PMSM), a series of transmission mechanisms, and the hydraulic control unit. As an integrative system of mechanics-electronics-hydraulics, the IBS has complex nonlinear characteristics, which challenge the accurate pressure control. Furthermore, it is a completely decoupled braking system, the pedal force doesn’t participate in pressure-building, so it is necessary to precisely identify driver’s braking intention. To improve the control accuracy of the system, this paper proposed a novel pressure
Zhu, Bing, Zhang, Yihan, Zhao, Jian, Chen, Zhicheng, Jin, Wanli
Painless Paper Patch Tests Glucose LevelsTBMG-3834501/01/2021
Researchers have been trying to develop a practical way to use microneedles — tiny needles less than 1 mm in length — for routine at-home medical monitoring. Microneedles are so short that they stay within the skin and do not make contact with any neurons, meaning that they cause no pain. Rather than extracting blood, they draw up fluid in the skin that contains most of the important biomarkers that blood tests look for. Several types of microneedles exist but until now, making a practical device that quickly analyzes the fluid has proved elusive.
Enclosure-in-Chamber Setup to Achieve Near-Zero Background Concentrations for Brake Emissions Testing2020-01-163410/05/2020
Measuring brake emission continues to be a challenging non-standardized task. Extensive research is ongoing and as seen in the work in progress presented at SAE Brake Colloquium and PMP meetings. However, open items include how to achieve lower background concentration and how to design the brake enclosure. A low background concentration is essential as brake events are short and some emissions are in the range of reported background levels. Hence these emissions are difficult to distinguish from the background level. Even more critical, a high background concentration can result in a wrong particle number emissions value, either overestimated, background counted as emissions, or underestimated, background level subtracted, and low emission events no longer detected and counted. Reducing the background level to less than 100 #/cm3 appeared to be quite challenging. Applying experience in validating automotive air filters and in industrial HVAC filters, an enclosure-in-chamber setup was
Lehmann, Martin J., Beck, Andreas, Kohn, Kevin, Pfannkuch, Steffen, Kilian, Alexander, Keller, Florian, Wörz, Tobias, Zessinger, Marco, Klein, Gunnar-Marcel
Comparison of the Effects of Different Biofuels on the Oxidation Stability of a Hydrocarbon Fuel2020-01-210109/15/2020
In this work, the effects of the addition of biofuels belonging to different chemical families on the oxidation stability of a conventional fuel surrogate (n-decane) have been investigated. Experiments have been performed in a PetroOxy apparatus, which is one of the references Rapid Small Scale Oxidation Test of the ASTM 7545 methods. When the pressure in the cell of the device decreases by 10% of the maximum pressure recorded, the time measured to reach this target value defines the Induction Period (IP). IP constitutes a quantitative measure of the oxidation stability of the fuel. In addition to the IP measurements for each biofuel / hydrocarbon fuel blend, organic peroxides produced in the liquid sample were quantified at the IP, using iodometric titration and ultraviolet-visible spectrophotometry. Different oxygenated biofuels have been studied in this work: diethyl ether, n-butanol, and cyclopentanone. Cyclohexane addition has also been considered to probe the effects of a non
El-Sayah, Zaki, Glaude, Pierre-Alexandre, Fournet, René, Sirjean, Baptiste
GDI Sprays with up to 200 MPa Fuel Pressure and Comparison of Diesel-like and Gasoline-Like Injector Designs2020-01-210409/15/2020
To address stricter emission limits, GDI develops to increased fuel pressure. Current gasoline injectors are already operating at a pressure of up to 35 MPa and an elevation is still promising lower particle emissions and increased efficiency. There have been only few studies of GDI sprays at pressures >50 MPa published. Contrary, in diesel engines injection pressure up to 250 MPa are common. GDI and diesel injector designs limit liquid penetration in different ways to avoid wall wetting, which has a negative impact on emissions in GDI combustion concepts. With elevated fuel pressure the question arises which design concept limits the penetration depth more effectively. To investigate the properties of high pressure sprays, a GDI injector (100 MPa max. fuel pressure) and an injector with diesel-like design are compared. High speed Shadowgraphy and Schlieren technique are used to gather information of liquid and vapor phase propagation. With Phase-Doppler-Anemometry (PDA) the diameter
Lehnert, Bastian, Conrad, Chris, Wensing, Michael
Experimental Investigation of Injection Strategies to Improve Intelligent Charge Compression Ignition (ICCI) Combustion with Methanol and Biodiesel Direct Injection2020-01-207209/15/2020
Applications of methanol and biodiesel in internal combustion engines have raised widespread concerns, but there is still huge scope for improvement in efficiency and emissions. The brand-new combustion mode, named as Intelligent Charge Compression Ignition (ICCI) combustion, was proposed with methanol-biodiesel dual fuel direct injection. In this paper, effects of injection parameters such as two-stage split-injections, injection timings, injection pressure and intake pressure on engine combustion and emissions were investigated at IMEP = 8, 10, and 12 bar. Results show that the indicated thermal efficiency up to 53.5% and the NOx emissions approaching to EURO VI standard can be obtained in ICCI combustion mode. Compared with the single direct injection for methanol, two-stage split-injection for methanol can form more precise and adaptive stratifications of concentration and reactivity which significantly increases the Ppeak and HRRmax in the cylinder and further reduces HC and CO
Huang, Guan, Li, Zilong, Zhao, Wenbin, Zhang, Yaoyuan, Qian, Yong, He, Zhuoyao, Lu, Xingcai
Effects of Ignition Control on Combustion Process Non-Repeatability in an Aircraft Radial Piston Engine2020-01-204409/15/2020
The ignition method significantly affects the combustion process in piston aircraft engines. This paper presents the results of bench tests of two variants of the radial piston aircraft engine: equipped with a standard magneto system and an electronic dual ignition system. The engine was tested in steady states for operating points defined by rotational speed and load. Their values corresponded to a load ranging from 50% of nominal power to take-off power. The ignition advance angle was constant for the engine equipped with ignition magnetos, while for the second engine variant it was determined by the developed algorithm introduced to the electronic ignition system control unit. The analysis of the combustion process was based on pressure measurements in one cylinder. The article focuses on the non-repeatability of engine operation described as a coefficient of variation for parameters such as indicated mean effective pressure, peak pressure, peak pressure angle, maximum rate of
Czarnigowski, Jacek Andrzej, Jaklinski, Piotr, Karpiński, Paweł
Determination of Kinematic Parameters for the Combustion of Jatropha Based Bio-Diesel2020-01-214809/15/2020
Laminar burning velocity is a fundamental measurement describing how a flame propagates into quiescent unburned mixture ahead of the flame at a specified pressure and temperature. Laminar burning velocity of bio-diesel air mixture has been studied in a spherical bomb, using the pressure - time records. Initial pressure, temperature is varied to cover a range from 1 bar - 4 bar and 443K-523K respectively. The range of measurements covered the equivalence ratio from 0.8 to 1.2. Pressure-time records have been used to calculate the flame velocity, burned gas fraction, flame position etc., using a simplified, two zone thermodynamic model, assuming equilibrium composition and homogenous mixture for the burned gases. It is also assumed frozen composition and isentropic compression for the unburned mixture. For each experimental run, instantaneous burning velocities are calculated in the range of 1.5 P0 to 0.75 Pmax and the laminar burning velocity values between the burned mass fraction of
Nain, Ajay
Soot Load Monitoring in Gasoline Particulate Filter Applications with RF-Sensors2020-01-217109/15/2020
With the start of Euro 6d regulations, gasoline particulate filters (GPF) have become standard equipment in European vehicles with gasoline-direct-injection engines. GPFs will also be broadly applied to meet the upcoming China 6 regulations. An existing challenge with GPFs is accurate soot load detection to manage the pressure loss across the exhaust system and to protect the GPFs from soot overload, which could potentially cause damage as result of uncontrolled soot oxidations. Systems with the GPF located in the under-floor position have a higher potential risk of soot overload due to lower temperatures, which can result in higher soot accumulation rates. The accuracy of existing soot estimation methods such as evaluation of the pressure drop of the soot-loaded GPF or model-based balancing of soot accumulation versus soot oxidation rates are sensitive to transient operating condition of a vehicle. Identifying an alternative method for accurate monitoring of the soot-loading state of
Nicolin, Per, Boger, Thorsten, Dietrich, Markus, Haft, Gerhard, Bachurina, Anastasiia
Evaluation of Geometry-Dependent Spray Hole Individual Mass Flow Rates of Multi-Hole High-Pressure GDI-Injectors Utilizing a Novel Measurement Setup2020-01-212309/15/2020
In order to optimize spray layouts of commonly used high-pressure injectors for gasoline direct injection (GDI) engines featuring multi-hole valve seats, a detailed understanding of the cause-effect relation between inner spray hole geometries and inner flow conditions, initializing the process of internal mixture formation, is needed. Therefore, a novel measurement setup, capable of determining spray hole individual mass flow rates, is introduced and discussed. To prove its feasibility, a 2-hole configuration is chosen. The injected fuel quantities are separated mechanically and guided to separate pressure tight measurement chambers. Each measurement chamber allows for time resolved mass flow rate measurements based on the HDA measurement principle (German: “Hydraulisches Druck-Anstiegsverfahren”). The setup is utilized for a systematic parameter study, comprising four almost identical generic real-size GDI-injector variants, where one spray hole per variant is subject to a diameter
Miller, Maximilian, Kuhnhenn, Maximilian, Samerski, Ingo, Lamanna, Grazia, Weigand, Bernhard
Experimental Investigation of Ignition Delay of Bio-Diesel and Its Blends2020-01-215209/15/2020
In this work, the ignitjion delay of bio-diesel and its blends with diesel at atmospheric pressure and temperature 8500C has been studied. The results are compared to those for diesel oil. Specifically, the suspended fuel droplet is inserted into a hot combustion chamber containing atmospheric air at temperatures which varied from 6250 - 8500C. The fuel droplet is suspended on the fine silica fibre wire of diameter 550 micron. It is mounted on rod and inserted in the hot combustion chamber at atmospheric condition. The ignition of the droplet is observed by optical circuit (optical sensor) and recorded by CRO. The ignition time is determined for calculating ignition delay. The results are plotted on the ignition delay ln(t) - 1/Temperature, K-1 coordinates to obtain the value of Activation Energy, EA. It has been found that the value of Activation Energy, EA is 44.3kJ for bio-diesel and 53.4kJ for diesel. The quantity of diesel increases the activation energy values from 45.3 kJ (10
Nain, Ajay
Numerical Investigation on GDI Spray under High Injection Pressure up to 100 MPa2020-01-210809/15/2020
In recent years, the increase of gasoline fuel injection pressure is a way to improve thermal efficiency and lower engine-out emissions in GDI homogenous combustion concept. The challenge of controlling particulate formation as well in mass and number concentrations imposed by emissions regulations can be pursued improving the mixture preparation process and avoiding mixture inhomogeneity with ultra-high injection pressure values up to 100 MPa. The increase of the fuel injection pressure in GDI homogeneous systems meets the demand for increased injector static flow, while simultaneously improves the spray atomization and mixing characteristics with consequent better combustion performance. Few studies quantify the effects of high injection pressure on transient gasoline spray evolution. The aim of this work was to simulate with OpenFOAM the spray morphology of a commercial gasoline injected in a constant volume vessel by a prototypal GDI injector. Different operating conditions were
Migliaccio, Marianna, Montanaro, Alessandro, Lucchini, Tommaso, Allocca, Luigi, Paredi, Davide
Hybridized Diesel Powertrains for LCV Applications to Meet the Stringent 2025 Standards for Pollutant- and CO 2 -Emissions2020-01-225209/15/2020
The ever-increasing pressure to reduce greenhouse gas (GHG) emissions from the transport sector poses challenges to the entire industry. Since the release of the new European CO2 fleet emission targets demanding a massive reduction in the upcoming years (-15%/-31% in 2025/2030 vs. the 2021 figures), substantial initiatives have been launched to ensure the development of affordable solutions. goals meeting the market requirements. Diesel powered vehicles and, especially Light-duty Diesel has been the main driver for CO2 emission reductions in recent years. These achievements were mainly based on improvement of combustion efficiency and reduction of mechanical losses. Based on this experience, it appears doubtful to achieve further significant fuel consumption and CO2 reductions with an improvement in engine technology alone. This reduction steps requested by the authorities call for the implementation of new technologies. The paper in hand describes the conceptual layout of the advanced
Koerfer, Thomas
Problems of Reducing Friction Losses of a Piston-Ring-Cylinder Configuration in a Combustion Piston Engine with an Increased Isochoric Pressure Gain2020-01-222709/15/2020
Currently, there is a tendency to increase the mean workable pressure in internal combustion engines, to reduce their cylinder volume and the number of cylinders in a balanced manner, depending on the vehicle's class and weight in order to improve the thermal and mechanical efficiency of the engine. An increased engine torque at a slight angular velocity results in an increase in the mean value of the unit pressure distribution of the piston rings, especially the upper sealing ring in the initial period of the expansion stroke, which limits the slip effect affecting the ability to form an oil film. The essence of validity of increasing the isochoric degree of pressure gain is the use of vehicles at low speeds with a high torque. Such selection of parameters ensures good motion dynamics at low fuel consumption. The use of sliding surfaces shape asymmetry significantly affects the course of the distribution of oil film on the cooperating working surfaces and the amount of oil scraped in
Wróblewski, Piotr, Iskra, Antoni
An Experimental Facility for Rapid Testing of SCR Systems2020-01-219209/15/2020
Urea-SCR (selective catalytic reduction) has become the principal technology used to lower NOx emissions in automotive compression ignition engines. Although the technology is well known and developed, the stricter emissions’ limits force engineers to implement new approaches to reduce warm-up time and improve the mixing process of the urea-water solution with the exhaust gases while avoiding a solid deposit formation. The exhaust system’s design is optimized using 3D numerical methods, but the validation of the design’s performance requires prototype testing on an engine dynamometer, where it is difficult to decouple and adjust the exhaust gas composition and temperature as in the numerical model; and thus it is problematic to verify the model. In this study we propose an experimental facility for rapid testing of SCR systems in simulated and precisely controlled engine-relevant conditions. The experimental set-up presented here uses heated atmospheric air with an addition of nitrogen
Boruc, Łukasz, Rogoz, Rafał, Bachanek, Jakub, Kapusta, Łukasz Jan, Jaworski, Piotr, Sutkowski, Marek, Teodorczyk, Andrzej, Jarosinski, Sebastian
Experimental Investigation of Injection Pressure Fluctuations Employing Alternative Fuels2020-01-212209/15/2020
Injection pressure oscillations are proven to determine considerable deviations from the expected mass flow rate, leading to the jet velocities non-uniformity, which in turn implies the uneven spatial distribution of A/F ratio. Furthermore, once the injector is triggered, these oscillations might lead the rail pressure to experience a decreasing stage, to the detriment of spray penetration length, radial propagation and jet break-up timing. This has urged the research community to develop models predicting injection-induced pressure fluctuations within the rail. Additionally, several devices have been designed to minimize and eliminate such fluctuations. However, despite the wide literature dealing with the injection-induced pressure oscillations, many aspects remain still unclear. Moreover, the compulsory compliance with environmental regulations has shifted focus onto alternative fuels, which represent a promising pathway for sustainable vehicle mobility. This scenario has motivated
Coratella, Carlo, Parry, Lewis, Xu, Hongming
Miniature Electronic Devices Work Under Extreme PressureTBMG-3764809/01/2020
Miniature devices have seamlessly found their way into pressure-sensing and energy-harvesting technologies because of their ability to be frequently stretched, compressed, or twisted. Despite their force-bearing abilities, it is still unclear if repeated physical stress can damage the working of these miniature devices, particularly if there is already a defect in their construction.
Air Dryer Test ProcedureJ2384_202008 (Current)08/26/2020
This SAE Recommended Practice establishes uniform test procedures for desiccant air dryers used in vehicles with compressed air systems per SAE J2383. Continuous flow desiccant air dryers are excluded from the scope of this document.
Truck and Bus Brake Supply and Control Components Committee
Cellulose-Based Sensor Simultaneously Measures Pressure, Temperature, and HumidityTBMG-3748108/01/2020
Researchers have developed a single sensor that combines the ability to measure pressure, temperature, and humidity simultaneously. The sensor has applications such as monitoring patients at home, robotics, electronic skin, functional textiles, surveillance, and security.
Supersonic Spike DiffuserTBMG-3682405/01/2020
The basic mode of operation for all passive supersonic diffusers is to enable a plume’s inherent power to drive the outer boundary of the exhaust jet to the diffuser wall so that the entire cross-section of the flow has a speed greater than that of sound. This allows mass removal from the area surrounding the nozzle via entrainment. The result is a low-pressure environment similar to the altitude at which the nozzle was designed to operate. Additionally, the nature of supersonic flow prevents pressure interference from the downstream environment.
Influence of Distributing Channel Configuration and Geometric Parameters on Flow Uniformity in Straight Flow-Field of PEM Fuel Cell2020-01-117304/14/2020
Gas distribution of proton exchange membrane fuel cells (PEMFCs) is mainly decided by flow field of bipolar plate. The improper design of distributing channel, nonuniform gas flow distribution and current density distribution among different straight channels are the leading factors that could tremendously undermine the performance and life expectancy of the cell. However, there is lack of research focusing on distributing channel in straight-parallel flow field. In this work, a three-dimensional numerical model of PEMFC cathode flow field is developed with CFD method to investigate the effects of configuration type and width of the distributing channel on pressure distribution in distributing channel and on reactant flow distribution, pressure drop and concentration distribution in multiple straight channel. Effects of electrochemical reaction and formation of water on the flow distribution are taken into consideration. By extending one group of z-type channels to four groups, a new
Wei, Huili, Chang, Guofeng, Liu, Jinling, Xu, Sichuan
Sensitivity Analysis of Aerodynamic Drag Coefficient to EPA Coastdown Ambient Condition Variation2020-01-066604/14/2020
The test cycle average drag coefficient is examined for the variation of allowable EPA coastdown ambient conditions. Coastdown tests are ideally performed with zero wind and at SAE standard conditions. However, often there is some variability in actual ambient weather conditions during testing, and the range of acceptable conditions is further examined in detail as it pertains to the effect on aerodynamic drag derived from the coastdown data. In order to “box” the conditions acceptable during a coastdown test, a sensitivity analysis was performed for wind averaged drag ((CDW ) ̅) as well as test cycle averaged drag coefficients (CDWC) for the fuel economy test cycles. Test cycle average drag for average wind speeds up to 16 km/h and temperatures ranging from 5C to 35C, along with variation of barometric pressure and relative humidity are calculated. The significant effect of ambient cross winds on coastdown determined drag coefficient is demonstrated.
Lounsberry, Todd, Tripp, John, Fadler, Gregory
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