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Viewing 241 to 270 of 8579
2016-04-05
Technical Paper
2016-01-0234
Roberto Cipollone, Davide Di Battista, Andrea Perosino, Federica Bettoja
Abstract The use of reciprocating internal combustion engines (ICE) dominates the sector of the in-the-road transportation sector, both for light and heavy duties. CO2 reduction is the technological driver, considering the severe worldwide greenhouse commitments. In ICE more than one third of the fuel energy used is rejected to the environment as thermal waste through the exhaust gases. Therefore, a greater fuel economy could be achieved, recovering this energy and converting it into useful electric power on board. Financial benefits will be produced in terms of fuel cost which will rebound similar benefits in terms of CO2 emitted. For long hauling vehicles, which run for thousands of miles, frequently at fixed engine operating conditions, this recovery appears very worthy of attention. In this activity, an ORC-based power unit was designed, built and tested fed by a heavy duty diesel engine, so contributing to the huge efforts on going in that specific sector.
2016-04-05
Technical Paper
2016-01-0228
Mengzuo Han, Gangfeng Tan, Xuexun Guo, Ruobing Zhan, Xuyang An, Weiye Xue, HongBo Kang
Abstract Vehicle exhaust waste-heat recovery with thermoelectric power generators can improve energy efficiency, as well as vehicle fuel economy. In the conventional structure, the hot-end of thermoelectric module is directly connected with the outer wall of the exhaust pipe, while the cold-end is connected with the water pipe’s outer wall of the vehicle engine cooling cycle. However, the variety of vehicle engine operating conditions leads to the instability of the hot-end temperature, which will reduce the generating efficiency of the thermoelectric modules and also shorten its service life. This research is on the basis of constructing a heat transfer oil circulation, and to study the action principles and implementation methods of it.
2016-04-05
Technical Paper
2016-01-0213
Andrea Alessandro Piovano, Laura Maria Lorefice, Giuseppe Scantamburlo
Abstract The aim of this work has been to develop an advanced methodology to model the car cabin cool down test. It has been decided to focus the attention on the fluid dynamics and thermal dynamics aspects of the phenomenon, trying to catch the correct heat transfer between the outside environment and the internal cabin with a thermal tool, together with an internal flows CFD simulation. To start with, an experimental cool down test was conducted in the FCA Italy climatic wind tunnel on a L0 segment vehicle, to get the correlation data and the boundary conditions required for the simulation: panel ducts air transient temperatures, wind tunnel air temperature and velocity, solar array load. The simulation was divided into two steps: steady state soak with a finite difference based thermal solver and transient cool down, coupling the thermal solver with a CFD one. In particular an advanced CFD/thermal coupled approach has been applied, using STAR-CCM+® and TAITherm® tools.
2016-04-05
Technical Paper
2016-01-0221
Roberto Monforte, Fabrizio Mattiello, Andrea Perosino, Fabrizio Porta, Susanna Paz, Pablo Lopez del Rincón
Abstract The adoption of a low-GWP refrigerant gas in MAC systems is mandatory from January 1st, 2017 according to the European Directive 2006/40/EC requirements for all new passenger cars, in order to gain their registration in the EU28 market. Following the work carried out in 2008 to support the FCA choice for the new types development, a further step was accomplished to evaluate the risk involved by the adoption of the low-GWP refrigerant gas R-1234yf in the MAC systems. This paper is focused on the activities held to enhance the 3D CFD method and its validation. In certain concentrations, R-1234yf could present a safety hazard to the vehicle occupants and, according to the ISO Standard Risk Scenario evaluation, 3D CFD tools are adopted to evaluate the ignition event associated with small or large leak in the passenger compartment. The method validation has been supported by both a simplified control volume “dummy cabin compartment” and an actual FCA vehicle.
2016-04-05
Technical Paper
2016-01-0209
Youcai Liang
Abstract This paper presents performance of a novel ECCS (electricity-cooling cogeneration system) based on cascade utilization of the waste heat of marine engines. The cogeneration system consists of a steam Rankine cycle and an NH3-H2O absorption refrigeration cycle with an expander. The steam Rankine cycle recycles the energy of both jacket coolant and exhaust gas of engine, while the absorption refrigeration cycle is employed to recover energy of the expanded steam at the turbine outlet in Rankine cycle. The performance of the waste heat recovery system is evaluated in terms of electricity, cooling capacity, equivalent electricity and exergy efficiency. The simulation results show that the novel ECCS exhibited a maximum net electricity output of 4561 kW, a maximum cooling capacity of 3197 kW, and a maximum equivalent electricity of 5233 kW.
2016-04-05
Technical Paper
2016-01-0212
Paras Kaushal, Satishchandra C. Wani
Abstract TeamIndus is the only Indian participant in the Google Lunar X Prize (GLXP). GLXP, also referred to as Moon 2.0, is an inducement prize space competition organized by the X Prize Foundation, and sponsored by Google. The mission objective is to soft land a rover on moon, travel 500 meters and transmit HD videos and images to Earth. Team Indus’s strategy is to design and realize a lunar lander that will deliver a rover on to the surface of the moon which will accomplish GLXP mission objectives. The mission configuration comprises of four phases- Earth orbits, moon orbits, descent and surface operations. The lander during its interplanetary journey from earth to moon is exposed to different thermal loads viz. solar load, earth IR and albedo, moon IR and albedo, cold space at 4K and eclipse periods. The lander is also exposed to high temperatures of thruster nozzle during orbital transfer maneuvers.
2016-04-05
Technical Paper
2016-01-0208
Xuzhi Du, Zhigang Yang, Hua Zhou, Qiliang Li, Zheyan Jin
Abstract The effect of jet geometry on flow, heat transfer and defrosting characteristics was numerically investigated for elliptic and rectangular impinging jets on an automobile windshield. Initially, various turbulence models within the commercial computational fluid dynamics (CFD) package FLUENT were employed and validated for a single jet, and the results indicated that the impinging jet heat transfer was more accurately predicted by the SST k -ω turbulence model, which was then utilized for this study. The aspect ratios (AR) of elliptic and rectangular jets were respectively 0.5, 1.0, and 2.0, with jet-to-target spacing h/d=2, 4 and jet-to-jet spacing c/d=4, and all those situations were numerically analyzed with the same air mass flow and jet open area. It was observed that the heat transfer coefficient and defrosting performance of the inclined windshield were significantly affected by the shape of the jet, and the best results were obtained with the elliptic jet arrangements.
2016-04-05
Technical Paper
2016-01-0211
Wang Yiping, Shuai Li, Chunhua Liu, Tao Wang, Panqi Chu
Abstract For vehicle thermoelectric generator, heat would be directly transferred into electricity by thermoelectric modules because there was temperature difference between heat exchanger and water tank. The electrical power generation was deeply influenced by temperature difference, temperature uniformity and topological structure of TEG. In previous works, increasing the difference of temperature would significantly enhance the power generation of TEG and inserted fins were always applied to enhance heat transfer in parallel-plate heat exchanger. But fins would result in a large backpressure which was not conductive to efficiency of the engine.In current study, to enhance heat transfer rates and outside surface temperature, cylindrical grooves on the top and bottom surface in heat exchanger was proposed. The cylindrical grooves could increase the heat transfer area and enhance the turbulence intensity, meanwhile there was no inserts in the fluid to block the flow.
2016-04-05
Technical Paper
2016-01-0205
Mattia De Rosa, Roy Douglas, Stephen Glover
Abstract The internal combustion (IC) engines exploits only about 30% of the chemical energy ejected through combustion, whereas the remaining part is rejected by means of cooling system and exhausted gas. Nowadays, a major global concern is finding sustainable solutions for better fuel economy which in turn results in a decrease of carbon dioxide (CO2) emissions. The Waste Heat Recovery (WHR) is one of the most promising techniques to increase the overall efficiency of a vehicle system, allowing the recovery of the heat rejected by the exhaust and cooling systems. In this context, Organic Rankine Cycles (ORCs) are widely recognized as a potential technology to exploit the heat rejected by engines to produce electricity. The aim of the present paper is to investigate a WHR system, designed to collect both coolant and exhausted gas heats, coupled with an ORC cycle for vehicle applications.
2016-04-05
Technical Paper
2016-01-0207
Ivan Arsie, Andrea Cricchio, Cesare Pianese, Vincenzo Ricciardi, Matteo De Cesare
Abstract In the last years, the research effort of the automotive industry has been mainly focused on the reduction of CO2 and pollutants emissions. In this scenario, concepts such as the engines downsizing, stop/start systems as well as more costly full hybrid solutions and, more recently, Waste Heat Recovery technologies have been proposed. These latter include Thermo-Electric Generator (TEG), Organic Rankine Cycle (ORC) and Electric Turbo-Compound (ETC) that have been practically implemented on few heavy-duty applications but have not been proved yet as effective and affordable solutions for passenger cars. The paper deals with modeling of ORC power plant for simulation analyses aimed at evaluating the opportunities and challenges of its application for the waste heat recovery in a compact car, powered by a turbocharged SI engine.
2016-04-05
Technical Paper
2016-01-0199
Bin Xu, Xiaobing Liu, John Shutty, Paul Anschel, Simona Onori, Zoran Filipi, Mark Hoffman
Abstract This paper presents an Organic Rankine Cycle (ORC) system model for heavy-duty diesel (HDD) applications. The dynamic, physics-based model includes: heat exchangers for parallel exhaust and EGR circuits, compressible vapor working fluid, distribution and flow control valves, a high pressure pump, and a reservoir. A finite volume method is used to model the evaporator, and a pressure drop model is included to improve the accuracy of predictions. Experimental results obtained on a prototype ORC system are used for model calibration and validation. Comparison of predicted and measured values under steady-state conditions is pursued first, followed by the analysis of selected transient events. Validation reveals the model’s ability to track real-world temperature and pressure dynamics of the ORC system.
2016-04-05
Technical Paper
2016-01-0100
Sushant Kishor Hingane
High-end vehicles with latest technology and autonomous driving experience have to bear the cost of increasing number of sensors on-board. It would be beneficial to reduce some of the sensors in the vehicle and make use of other available resources, retaining the same functionality. This paper discusses a novel technique of estimating the weight of seat occupant from an already existing DC motor without using additional pressure sensors. Passenger weight information is important for seat-belt reminder system as well as supplemental restraint system that will decide the air-bag deployment. The mathematical model for a series-type DC motor is analyzed and simulated using MATLAB. Further, results of the experiment performed on a lower capacity motor are shared and compared with the simulation results. Formulating a linear relation gives a possibility to develop a device for occupant weight measurement inside the high-end vehicles.
2016-04-05
Technical Paper
2016-01-0080
Hiroyuki Miyake
Abstract This paper explains a performance enhancement of the lane guidance function in car navigation systems. In order to achieve intuitive lane guidance, a function is considered that displays lane guidance on an image of the front scene that matches what drivers actually see outside the vehicle. Therefore, two developed items were lane accurate positioning based on image recognition and augmented reality visualization that renders lane guidance images overlaid on the scenery of the road ahead. The eye glance time to the navigation screen has been reduced in a comparison test with a conventional lane guidance method. It is confirmed that this lane guidance function is more intuitive than the conventional method.
2016-04-05
Technical Paper
2016-01-1683
Blago B. Minovski, Lennart Lofdahl, Peter Gullberg
Abstract Presented are results from numerical investigations of buoyancy driven flow in a simplified representation of an engine bay. A main motivation for this study is the necessity for a valid correlation of results from numerical methods and procedures with physical measurements in order to evaluate the accuracy and feasibility of the available numerical tools for prediction of natural convection. This analysis is based on previously performed PIV and temperature measurements in a controlled physical setup, which reproduced thermal soak conditions in the engine compartment as they occur for a vehicle parked in a quiescent ambient after sustaining high thermal loads. Thermal soak is an important phenomenon in the engine bay primarily driven by natural convection and radiation after there had been a high power demand on the engine. With the cooling fan turned off and in quiescent environment, buoyancy driven convection and radiation are the dominating modes of heat transfer.
2016-04-05
Technical Paper
2016-01-1588
Abdalla Abdel-Rahman, Martin Agelin-Chaab, Gary Elfstrom, John Komar
Abstract Wind tunnels with integrated aerodynamic and thermodynamic testing with yaw capabilities are not common. In this study however, an integrated aerodynamic and thermodynamic testing system with yaw capabilities is developed and applied in the climatic wind tunnel at the University of Ontario-Institute of Technology (UOIT). This was done by installing an incremental force measuring system (FMS) on the large turntable that features a chassis dynamometer. The testing system was utilized to implement an integrated aero-thermal test on a full-scale race car. An efficient testing protocol was developed to streamline the integrated testing process. The FMS was used to enhance the test car’s stability, cornering speed, and fuel efficiency by using aerodynamic devices. These objectives were achieved by installing a high rear wing to increase the rear downforce, a modified front splitter extension to produce a front downforce gain, and front canards to contribute to drag reduction.
2016-04-05
Technical Paper
2016-01-0664
Ahmed E. Hassaneen, Wael I. A. Aly, Gamal Bedair, Mohammed Abdussalam
Abstract The thermal performance of an ammonia-water-hydrogen absorption refrigeration system using the waste exhaust gases of an internal combustion diesel engine as energy source was investigated experimentally. An automotive engine was tested in a bench test dynamometer, with the absorption refrigeration system adapted to the exhaust pipe via a heat exchanger. The engine was tested for different torques (15 N.m, 30 N.m, and 45 N.m). The exhaust gas flow to the heat exchanger built on the generator was controlled manually using two control valves. The refrigerator reached a steady state temperature between 10 and 14.5°C about 3.5 hours after system start up, depending on engine load. The maximum coefficient of performance was 0.10 obtained for the controlled exhaust mass flow case at torque 30 Nm after 3hrs from system startup.
2016-04-05
Technical Paper
2016-01-0548
Estefanía Hervas-Blasco, Emilio Navarro-Peris, José Corberan, Alex Rinaldi
Abstract Nowadays, more than 50% of the fuel energy is lost in CNG Engines. While efforts to increase their efficiency have been focused mainly on the improvement of the combustion process, the combustion chamber and the reduction of friction losses, heat losses still remain the most important inefficient factor. A global strategy in which several energy recovery strategies are implemented could lead to engine improvements up to 15%. Therefore, the development of accurate models to size and predict the performance of the integrated components as well as to define an optimized control strategy is crucial. In this contribution, a model to analyze the potential of a new powertrain based on the electrification of the main auxiliaries, the integration of a kinetic energy recovery system and the exhaust gases heat recovery through a thermoelectric generator and a turbo-component is presented.
2016-04-05
Technical Paper
2016-01-0254
Gursaran D. Mathur
Field tests were conducted on a late full sized sedan with the HVAC unit operating in both Recirculation and OSA modes to monitor build-up of the CO2 concentration inside the cabin and its influence on occupant’s fatigue and alertness. These tests were conducted during 2015 summer on interstate highways with test durations ranging from 4 to 7 hours. During the above tests, fatigue or tiredness of the occupants (including CO2 levels) was monitored and recorded at 30 min intervals. Based on this investigation it is determined that the measured cabin concentration levels reaches ASHRAE (Standard 62-1999) specified magnitudes (greater than 700 ppm over ambient levels) with three occupants in the vehicle. Further, the occupants did show fatigue when the HVAC unit was operated in recirculation mode in excess of 5 hours. Further details have been presented in the paper.
2016-04-05
Technical Paper
2016-01-0203
Yadong Deng, Chunhua Liu, Panqi Chu
Abstract In order to make full use of engine exhaust heat, the thermoelectric module been used to contribute to thermoelectric power generation in the automotive. At present, the thermoelectric generators (TEGs) have been developing with continuously advances in thermoelectric technology. And almost all of the existing thermoelectric technologies are adding a gas tank to the vehicle exhaust system which increases the exhaust back pressure and occupying excessive space of the vehicle chassis. In this study, a new TEG integrated with a front silencer muffler (FMTEG) is proposed. The muffler is reshaped as the heat exchanger which has a hexagon cross-section. The water tank and clamping mechanism have been redesigned for the new heat exchanger. The FMTEG system’s dimensions are small that can well meet the installation requirements and has a good compatibility with the vehicle exhaust system.
2016-04-05
Technical Paper
2016-01-0198
Sudhi Uppuluri, Hemant R. Khalane, Yogesh Umbarkar, Ajay Naiknaware
Abstract Vehicle development teams find it challenging to predict what their Heating, Ventilation and Air-Conditioning (HVAC) module performance will be for cold ambient (∼ -20 deg. C) test cycles such as defrost and cabin warm-up before the car is built. This uncertainty in predictions comes from varying engine heat rejection to coolant due to cold cylinder wall temperatures, calibration changes and degraded performance of various components within the cooling system such as the coolant pump owing to higher viscosity of the coolant. Measuring engine heat rejection at cold ambient is extremely difficult as the engine warms up as soon as it is fired. Multiple measurement points require long lead time to soak to the cold target temperature. It is a common practice to adjust engine calibration parameters to warm up coolant as fast as possible for an adequate defrost and cabin warm-up performance.
2016-04-05
Technical Paper
2016-01-0204
Igor Gritsuk, Yurii Gutarevych, Vasyl Mateichyk, Vladimir Volkov
Abstract The article discusses the features of applying vehicular engine heating system with phase-transitional thermal accumulator. The peculiarity of the presented system is that it uses thermal energy of exhaust gases from internal combustion engine during its operation to accumulate heat. The results of experimental studies of heating the vehicular engine are shown. The article describes the structure of information package for studying the internal combustion engine of a vehicle with heating system and thermal accumulator during the start and after-start heating. The package allows engine performance parameters and engine thermal development to be estimated from distance within intelligent transport systems. Using phase-transitional thermal accumulator in engine coolant heater system (case studied: G4GC (4FS 8.2 / 9.35) of KIA CEE'D 2.0 5MT2) reduces time for heating by 17.8 - 68.4% and fuel consumption by 19.5 - 56.25%.
2016-04-05
Technical Paper
2016-01-0576
Chad Koci, Kenth Svensson, Christopher Gehrke
Abstract A two-zone NOx model intended for 1-D engine simulations was developed and used to model NOx emissions from a 2.5 L single-cylinder engine. The intent of the present work is to understand key aspects of a simple NOx model that are needed for predictive accuracy, including NOx formation and destruction phenomena in a DI Diesel combustion system. The presented two-zone model is fundamentally based on the heat release rate and thermodynamic incylinder data, and uses the Extended Zeldovich mechanism to model NO. Results show that the model responded very well to changes in speed, load, injection timing, and EGR level. It matched measured tail pipe NOx levels within 20%, using a single tuning setup. When the model was applied to varied injection rate shapes, it showed correct sensitivity to speed, load, injection timing, and EGR level, but the absolute level was well outside the target accuracy. The same limitation was seen when applying the Plee NOx model.
2016-04-05
Technical Paper
2016-01-0641
Thomas De Cuyper, Sam Bracke, Jolien Lavens, Stijn Broekaert, Kam Chana, Michel De Paepe, Sebastian Verhelst
Abstract To optimize internal combustion engines (ICEs), a good understanding of engine operation is essential. The heat transfer from the working gases to the combustion chamber walls plays an important role, not only for the performance, but also for the emissions of the engine. Besides, thermal management of ICEs is becoming more and more important as an additional tool for optimizing efficiency and emission aftertreatment. In contrast little is known about the convective heat transfer inside the combustion chamber due to the complexity of the working processes. Heat transfer measurements inside the combustion chamber pose a challenge in instrumentation due to the harsh environment. Additionally, the heat loss in a spark ignition (SI) engine shows a high temporal and spatial variation. This poses certain requirements on the heat flux sensor. In this paper we examine the heat transfer in a production SI ICE through the use of Thin Film Gauge (TFG) heat flux sensors.
2016-04-05
Technical Paper
2016-01-0651
Masaki Harada, Takashi Yasuda, Shota Terachi, Sergio Pujols, Jason R. Spenny
Abstract Due to the recent trend emphasizing on environmental friendly, engine supercharger downsizing technology has been under development globally. In this report, the technical knowledge for high performance and high quality water-cooled CAC development is provided. For higher cooling performance, the optimum fin and tube core matrix water-cooled CAC, delivering best performance and quality have been developed. For higher reliability against thermal stress, the detail specifications of water-cooled CAC based on the transient analysis and the simulation technology have been established.
2016-04-05
Technical Paper
2016-01-0217
Somnath Sen, Mayur Selokar, Diwakar Nisad, Kamal Kishore
Abstract Adequate visibility through the vehicle windshield over the entire driving period is of paramount practical significance. Thin water film (fog) that forms on the windshield mainly during the winter season would reduce and disturb the driver’s visibility. This water film originates from condensing water vapor on inside surface of the windshield due to low outside temperatures. Primary source of this vapor is the passenger’s breath, which condenses on the windshield. Hot and dry air which impinges at certain velocity and angle relative to the windshield helps to remove the thin water film (defogging) and hence improves driver’s visibility. Hence a well-designed demisting device will help to eliminate this fog layer within very short span of time and brings an accepted level of visibility. An attempt is made here to design and develop a demisting device for a commercial vehicle with the help of numerical and analytical approach and later on validated with experimental results.
2016-04-05
Technical Paper
2016-01-0188
Elankathiravan Mathivanan, Liping Liu
In the present work, the effect of various nanofluids on convective heat transfer performance in an automotive radiator was analyzed based on measured nanofluid properties. Al2O3, TiC, SiC, MWNT (multi-walled nanotube) and SiO2 nanoparticles ranging between 1 and 100 nm in size were dispersed in distilled water to form nanofluids. An ultrasonic generator was used to provide uniform particle dispersion in the fluid and keep the mixture stable for a long period of time. The impact of various particle types and their volume concentration on fluid properties such as density, thermal conductivity and viscosity were experimentally analyzed. It is observed that the nanofluid properties increased with the increase in particle volume concentration. TiO2 nanofluids were observed to show the highest increase in density (2.6% higher than the base fluid at a 1% vol. concentration) and also the largest enhancement in thermal conductivity (7.5% augmentation at 1% concentration).
2016-04-05
Technical Paper
2016-01-0248
Mingyu Wang, Edward Wolfe, Timothy Craig, Tim J. Laclair, Omar Abdelaziz, Zhiming Gao
Abstract Without the waste heat available from the engine of a conventional automobile, electric vehicles (EVs) must provide heat to the cabin for climate control using energy stored in the vehicle. In current EV designs, this energy is typically provided by the traction battery. In very cold climatic conditions, the power required to heat the EV cabin can be of a similar magnitude to that required for propulsion of the vehicle. As a result, the driving range of an EV can be reduced very significantly during winter months, which limits consumer acceptance of EVs and results in increased battery costs to achieve a minimum range while ensuring comfort to the EV driver. To minimize the range penalty associated with EV cabin heating, a novel climate control system that includes thermal energy storage has been designed for use in EVs and plug-in hybrid electric vehicles (PHEVs). The system uses the stored latent heat of an advanced phase change material (PCM) to provide cabin heating.
2016-04-05
Technical Paper
2016-01-0722
Yoshihiro Funayama, Hiroshi Nakajima, Kiyohiro Shimokawa
Abstract In order to improve the brake thermal efficiency of the engine, such as cooling and friction losses from the theoretical thermal efficiency, it is necessary to minimize various losses. However, it is also essential to consider improvements in theoretical thermal efficiency along with the reduction of the various losses. In an effort to improve the brake thermal efficiency of heavy-duty diesel engines used in commercial vehicles, this research focused on two important factors leading to the engine's theoretical thermal efficiency: the compression ratio and the specific heat ratio. Based on the results of theoretical thermodynamic cycle analyses for the effects of the above two factors, it was predicted that raising the compression ratio from a base engine specification of 17 to 26, and increasing the specific heat ratio would lead to a significant increase in theoretical thermal efficiency.
2016-04-05
Technical Paper
2016-01-0770
Filip Cernik, Jan Macek, Christoph Dahnz, Sebastian Hensel
A quasi-dimensional dual fuel combustion model is proposed for a large 2-stroke marine engine. The introduced concept accounts for both diffusion combustion of the liquid pilot fuel and the flame front propagation throughout the gaseous premixed charge. For the pilot fuel case a common integral formulation defines the ignition delay whereas a time scale approach is incorporated for the combustion progress modeling. In order to capture spatial differences given by the scavenging process and the admission of the gaseous fuel, the cylinder volume is discretized into a number of zones. The laws of conservation are applied to calculate the thermodynamic conditions and the fuel concentration distribution. Subsequently, the ignition delay of the gaseous fuel-air mixture is determined by the use of tabulated kinetics and the ensuing oxidation is described by a flame velocity correlation.
2016-04-05
Technical Paper
2016-01-0763
Lianhao Yin, Gabriel Ingesson, Per Tunestal, Rolf Johansson, Bengt Johansson
Abstract Partially Premixed Combustion (PPC) is a promising combustion concept with high thermodynamic efficiency and low emission level, and also with minimal modification of standard engine hardware. To use PPC in a production oriented engine, the optimal intake charge conditions for PPC should be included in the analysis. The experiments in this paper investigated and confirmed that the optimal intake conditions of net indicated efficiency for PPC are EGR between 50% and 55% as possible and the lambda close to 1.4. Heat-transfer energy and exhaust gas waste-energy contribute to the majority of the energy loss in the engine. The low EGR region has high heat-transfer and low exhaust gas enthalpy-waste, while the high EGR region has low heat-transfer and high exhaust gas waste-enthalpy. The optimal EGR condition is around 50% where the smallest energy loss is found as a trade-off between heat transfer and exhaust-gas enthalpy-waste.
Viewing 241 to 270 of 8579