Criteria

Text:
Display:

Results

Viewing 91 to 120 of 110594
2017-10-08
Technical Paper
2017-01-2281
Lang Jiang, Zhe Kang, Zhehao Zhang, Zhijun Wu, Jun Deng, Zongjie Hu, Liguang Li
It is a widely consensus that the ambient temperature direct water injection can be utilized to reduce nitric oxides emissions in both diesel and gasoline engine. Since the proposal of water injection technology, there are many researches studying the effect of different direct water injection strategies on nitric oxides emissions and engine performance which generally lead to lower nitric oxides emissions while combustion efficiency deteriorated. The present work aimed at optimizing diesel engine combustion efficiency with the decrement of nitric oxides emissions using optimized water injection strategy. The engine has been modified based on a two cylinder mechanical pump diesel engine into common rail diesel engine with capability in direct water injection. The direct water injection system is designed and manufactured independently, an air-fluid booster is utilized to establish the water injection pressure up to 40MPa.
2017-10-08
Technical Paper
2017-01-2280
Yuzuru Nada, So Morimoto, Yoshiyuki Kidoguchi, Ryu Kaya, Hideaki Nakano, Shinichi Kobayashi
In our previous studies, we have developed natural gas engines operating under lean conditions to improve thermal efficiency and emission characteristics. We applied a sub-chamber injection system to our engines, in which natural gas is directly injected into a combustion sub-chamber in order to completely separate stoichiometric mixture in the sub-chamber from ultra-lean mixture in the main chamber. The results obtained from engine tests demonstrated excellent performance of our engines in view point of efficiency and NOx emissions. However, we have poor knowledge of mixture distributions in the combustion chambers to understand the mechanism of the improvements. The aim of this paper is to clarify the mixture formation in combustion chambers by means of numerical simulations in the combustion chamber with and without the sub-chamber at a variety of operating conditions.
2017-10-08
Technical Paper
2017-01-2283
Anand Prabu Kalaivanan, Gnanasekaran Sakthivel
Electronic Fuel Injection Systems have revolutionised Fuel Delivery and Ignition timing in the past two decades and have reduced the Fuel Consumption and Exhaust Emissions, ultimately enhancing the Economy and Ecological awareness of the engines. But the ignition/injection timing that commands the combustion is mapped to a fixed predefined table which is best suited during the stock test conditions. However continuous real time adjustments by monitoring the combustion characteristics prove to be highly efficient and be immune to varying fuel quality, lack of transient performance and wear related compression losses. Addressing Fuel Quality Issues: For developing countries, Automobile Manufacturers have been Tuning the Ignition/Injection timing Map assuming the worst possible fuel quality. Conventional knock control system focus on engine protection only and doesn't contribute much in improving thermal efficiency.
2017-10-08
Technical Paper
2017-01-2321
Timothy H. Lee, Han Wu, Alan Hansen, Tonghun Lee, Gang Li
Bio-butanol has been considered as a promising alternative fuel for transportation due to its advantageous physical and chemical properties, but the high recovery and dehydration cost reduced its competitiveness in the fuel market. In order to achieve the bio-fuel advantage, the current work tried to apply and evaluate the upstream products of bio-butanol, Isopropanol-Butanol-Ethanol (IBE). These mixtures are obtained by ABE fermentation and IBE fermentation respectively, as alternative diesel fuel. Isopropanol-Butanol-Ethanol (IBE) is an intermediate product in the IBE fermentation process for producing bio-butanol. The study was carried out in an AVL 5402 single-cylinder diesel engine fueled by IBE-Diesel, ABE-Diesel and neat diesel. During the experiments, the engine speed, engine loads, and injection timings were varied. The results showed that with the addition of IBE in diesel fuel, the engine can still operate smoothly with a set pilot injection.
2017-10-08
Technical Paper
2017-01-2335
Tiantian Yang, Tie Wang, Jing Qiao, Ji Gao, Yizhuo Feng, Dandan Sun
F-T diesel which is made from coal to liquid by Fischer-Tropsch synthesis can be used as a clean alternative fuel of diesel engine. But, F-T diesel has the disadvantage of high cost and low viscosity. Combined with the low cost of methanol and high viscosity of biodiesel, F-T diesel would be modified to be the Methanol-F-T diesel-biodiesel multiple fuel (MBFT). Considering the miscible between alcohols and hydrocarbons, this paper carried on a series of stability tests and found that the n-decanol was the optimum co-solvent of MBFT. Then, MBFTs were the blends of be methanol varying proportions (i.e. 0%, 5%, 10% vol), biodiesel (10% vol), F-T diesel and n-decanol (recorded as M0, M5, M10 and M15). The increasing methanol proportion would cause the increase of the oxygen content of the mixed fuels while the heat value would be reduced, as well as the surface tension and cetane number.
2017-10-08
Technical Paper
2017-01-2340
Shashank Mishra, Anand Krishnasamy
Owing to a rapid rise in global energy demand in various sectors including power, agriculture and transport, there is a tremendous increase in demand for conventional diesel fuel. Biodiesel are emerging as renewable alternative to diesel with better emission characteristics (except nitric oxides). The biodiesel could be produced from various feedstock including vegetable oils, animal fats, algae, etc. and thus, vary significantly in their fatty acid methyl ester composition and physico-chemical properties and thereby, engine performance and emissions. In the present work, the effects of biodiesel compositional variations in conjunction with changes in engine load and injection timings are captured using a multi-linear regression model which is applied to predict performance and emission characteristics of a single cylinder diesel engine.
2017-10-08
Technical Paper
2017-01-2371
Hiroki Kambe, Naoto Mizobuchi, Eriko Matsumura
Diesel Particulate filter (DPF) is installed as after treatment device of exhaust gas in diesel engine, and it collects Particulate Matter (PM). However, as the operation time of engine increases, the PM is accumulated in the DPF, resulting in deterioration of PM collection efficiency and increase in pressure loss. Therefore, Post injection has been attracted attention as the DPF regeneration method for burning and removing PM in the DPF. But, Post injection causes oil dilution when fuel is injected at the middle to late stage of expansion stroke. Oil dilution are concern to decrease the stroke lubricity of piston movement and the thermal efficiency. In order to estimate deposition amount of fuel spray that influences oil film, we should elucidate spray impingement behavior on wall surface of oil film, to research more from the behavior of in-cylinder spray during post injection.
2017-10-08
Technical Paper
2017-01-2373
Jun Kaniyu, Shogo Sakatani, Eriko Matsumura, Takaaki Kitamura
Diesel Particulate Filter (DPF) is a very effective aftertreatment device to limit particulate emissions from diesel engines. As the amount of soot collected in the DPF increases, the pressure loss increases and the purification rate decreases. Therefore, DPF regeneration needs to be performed. Injected fuel into the exhaust line upstream of the Diesel Oxidation Catalyst (DOC), hydrocarbons are oxidized on the DOC, which increases the exhaust gas temperature at the DPF inlet. Also, it is necessary that the injected fuel is completely vaporized before entering the DOC, and uniformly mixed with the exhaust gases in order to make the DOC work efficiency and durably. However, ensuring complete evaporation and an optimum mixture distribution in the exhaust line are challenging. Therefore, it is important that the fuel spray feature are grasped to perform DPF regeneration effectively. The purpose of this study is the constructing a simulation model.
2017-10-08
Technical Paper
2017-01-2378
Takayuki Ogata, Mikio Makino, Takashi Aoki, Takehide Shimoda, Kyohei Kato, Takahiko Nakatani, Koji Nagata, Claus Dieter Vogt, Yoshitaka Ito, Dominic Thier
In order to meet the challenging CO2 targets beyond 2020 despite keeping high performance engines, Gasoline Direct Injection (GDI) technology usually combined with charged aspiration is expanding in the automotive industry. While providing more efficient powertrains to reduce fuel consumption one side effect of GDI is the increased particle formation during the combustion process. For the first time for GDI from September 2014 there is a Particle Number (PN) limit of 6E12 #/km, which will be further reduced by one order of magnitude to 6E11 #/km effective from September 2017 to be the same level as applied to Diesel engines. In addition to the PN limit of the certification cycle NEDC further certification of Real Driving Emissions (RDE) including portable PN measurements are under discussion by the European Commission. RDE test procedure requires stable and low emissions in a wide range of engine operations and durable over a distance of 160 000 km.
2017-10-08
Technical Paper
2017-01-2390
Hongxue Zhao, Daliang Jing, Yinhui Wang, Shi-jin Shuai, Changle PANG
In this paper, the impacts of Aromatic, Olefin and Ethanol on the formations of PAHs (poly-aromatic hydrocarbons) and VOCs (volatile organic compounds) in the gasoline engine was experimentally and numerically investigated. The objective of this study is to describe the formation process of the soot precursors including one ring to four ring benzene(A1-A4). In order to better understand the effects of the fuel properties on the formations of PAHs and VOCs, four test fuels including pure gasoline, gasoline with higher aromatics content, gasoline with higher olefin content, and gasoline with extra 10% ethanol content were experimentally studied. At the same time, these aspects were also numerically investigated in the CHEMKIN code by using premixed laminar flame model. The results showed that higher aromatics content in gasoline will lead to much higher PAHs and VOCs emissions.
2017-10-08
Technical Paper
2017-01-2394
Ning Xu, Di-ming Lou, Ji-yao Liu, Piqiang Tan, Zhiyuan Hu
The Extended-range electric transit bus (EREbus) equipped with the auxiliary power unit (APU) using high efficient diesel engine as power source can reduce the cost of power battery and is an ideal transitional powertrain architecture to the pure electric drive. Based on chassis tests of a 12m long EREBus, fuel consumption and emission characteristics during charge sustain stage effected by temperature of the EREBus are researched. The APU of EREBus starts to work around just one point with best efficiency and lower emission when the state of charge (SOC) is too low and stop when the SOC is high, which aims to lower fuel consumption, and as a result, even during charge sustain stage, the fuel consumption per hundred kilometers of Rebus is only 22.84 L and emissions also decrease dramatically except for the ultrafine-particle number emission on account of better combustion.
2017-10-08
Technical Paper
2017-01-2397
Zhan Gao, Lei Zhu, Xinyao Zou, Chunpeng Liu, Zhen Huang
Biodiesel is a potential alternative fuel which can meet the growing need for sustainable energy. Partially premixed compression ignition (PPCI) is an important low-temperature combustion strategy to reduce NOx and soot emission of diesel engines. To investigate partial premixing impact on particle formation in flames of biodiesel or biodiesel surrogates, an experimental study was performed to compare the soot morphology and nanostructure evolution in laminar co-flow methyl decanoate non-premixed flame (NPF) and partially premixed flame (PPF). The thermophoretic sampling technique was used to capture particles along flame centerlines. Soot morphology information and volume fraction were obtained from TEM analysis and nanostructure features were evaluated by HR-TEM. With primary equivalence ratio of 19, gas temperature of PPF is higher along flame centerline compared with NPF. The results show an initially stronger sooting tendency in PPF at lower positions.
2017-10-08
Technical Paper
2017-01-2402
Yoshinori Otsuki, Shigemi Tochino, Kenji Kondo, Kazuhiko Haruta
Fine particle emissions from engine exhaust have attracted attention, because of concern of higher deposition fraction in alveoli. Solid particle number (PN) emission regulations have been implemented mainly in Europe in order to reduce fine particle emissions and improve sensitivity of conventional gravimetric particulate matter mass measurement methodology. Since it was observed that sizes of solid particles in exhaust of conventional internal combustion engine technologies are mainly distributed above 30 nm and sensitivity to volatile particles can be reduced, the current PN measurement methodology can identify particle number emissions just to bigger particle than 23 nm. Necessity in measurement of smaller particles than 23 nm is still under discussion. Despite of implementation of stricter emission regulations, pollutant levels in environment have not been improved sufficiently.
2017-10-08
Technical Paper
2017-01-2404
Douglas Ball, David Lewis, David Moser, Sanket Nipunage
Federal Test Procedure (FTP) emissions were measured on a 4 cylinder 2.4L Malibu PZEV vehicle with 10 and 30ppm sulfur fuel while varying the PGM (Platinum Group Metals) of the close-coupled and under floor converters. Base CARB PH-III certification fuel was used. Three consecutive FTP’s were used to measure the impact of fuel sulfur and catalyst PGM loading combinations. In general, reducing fuel sulfur and increasing catalyst PGM loadings decreased FTP emissions. It is estimated that a fuel sulfur change from 30 to 10 ppm may save $100 in catalyst system PGM.
2017-10-08
Technical Paper
2017-01-2407
Michael Bardon, Greg Pucher, David Gardiner, Javier Ariztegui, Roger Cracknell, Heather Hamje, Leonardo Pellegrini, David Rickeard
Low Temperature Combustion using compression ignition may provide high efficiency combined with low emissions of oxides of nitrogen and soot. This process is facilitated by fuels with lower cetane number than standard diesel fuel. Mixtures of gasoline and diesel (“dieseline”) may be one way of achieving this, but a practical concern is the flammability of the headspace vapours in the vehicle fuel tank. A mathematical model is presented that predicts the flammability of the headspace vapours in a tank containing mixtures of gasoline and diesel fuel. Fourteen hydrocarbons and ethanol represent the volatile components. Heavier components are treated as non-volatile diluents in the liquid phase. The non-ideality of the blends of hydrocarbons and ethanol is accounted for using activity coefficients.
2017-10-08
Technical Paper
2017-01-2411
Henry Guo, Wenchuan Jia, DeDong Xie
A smart waste gate (WG) turbocharger controls boost by bypassing turbine flow through the WG port which allows optimizing both low and high speed engine performance. However, the WG port in the turbine housing involves much complex geometry which leads to potentially higher thermal stress and plastic strain if design is improper. This paper first presents the common thermal cracking problems at port zone and then shows finite element analysis (FEA) results for one design. The predicted location correlates well with the observed failure port location. A design study with key parameters for the port is conducted under same boundary conditions. Key parameters include height H, inner diameter D and inner diameter fillet r of the port. Totally 13 designs are analyzed under packaging and performance limitation. Accumulated plastic strain (APS) from FEA is used to evaluate different designs. Curves are plotted to show the relationship between APS and design parameters.
2017-10-08
Technical Paper
2017-01-2423
Xiaoming Ye, Yan Fu, Wei Li, Yuze Jiang, Shixin Zhu
As the key components of internal combustion engine(ICE), the crankshaft main bearings are used to support the crankshaft and connecting rod mechanism whose rotary motion realizes the energy conversion from heat energy to mechanical power in cylinder. The lubrication performances and wear life of crankshaft main bearings directly affect ICE working efficiency and reliability. Therefore, it is very important to study the lubrication performances of crankshaft main bearings. In this paper, a 16V marine diesel engine was studied. Based on the AVL-Designer software platform, a dynamic model of crankshaft and connecting rod mechanism and a hydrodynamic lubrication model of crankshaft main bearing were built. The numerical analyses were carried out on the lubrication performances of crankshaft main bearings under different speed conditions.
2017-10-08
Technical Paper
2017-01-2421
Dongkang Cheng, Xiaori Liu
With the enhancement of power density, the thermal load of internal combustion engine becomes an increasingly serious problem, the influence of heat load on the frictional power loss of piston ring is more prominent. A mixed lubrication model is established for the piston ring-cylinder liner system of a diesel engine, the influence of temperature change on the frictional power loss of piston ring-cylinder liner system is investigated. The maximum temperature ranges of the first ring, the second ring and the oil ring are 40 degrees Celsius independently, and the maximum temperature range of the cylinder liner is 20% of its temperature.
2017-10-08
Technical Paper
2017-01-2424
Shemin Zhang, Huaping Li, Tao Chen, Nan Jiang, Xinzhen Tan, Limei Deng, Qingsong Xia, Paul Kapus, Mingtang Ma, Wei Li, Junqiang Zhang, Qingjun Ma, Yong Xia
In recent years, more attentions have been paid to stringent legislation on fuel and emissions. Turbocharged downsizing DI engine is playing an increasing vital role in OEM’s powertrain strategies. Dongfeng Motor (DFM) has developed a new type of 1.0-liter 3 cylinder TGDI gasoline engine to meet the requirements of China 4th stage fuel consumption regulations and the China 6 emission standards. In this paper, the concepts of DFM 3-cylinder 1.0TGDI gasoline engine are explored to meet the powerful performance (torque 190Nm/1500-4500rpm and power 95kW/5500rpm), excellent part-load BSFC and NVH targets to ensure the drivers could enjoy the powerful output in quiet and comfortable environment without concerning about the fuel cost and pollution. The combustion system with side-mounted 6-hole direct injector and 200bar injection pressure has been optimized by CFD simulation and transparent engine investigation.
2017-10-08
Technical Paper
2017-01-2433
Fengqin Huang, Wenxin CAI, Zhiming Zhang, Wenlong Zhang, Laifeng Shi, Xin Li, Bernhard Kaltenegger, Daniele Suzzi, Werner Schrei, Karl Weihrauch
Nowadays high engine thermal efficiency is the mainstream of the gasoline engine development, and the strict control of the design period, which lead to the cylinder head design become more and more difficult. How to get the optimal design of cylinder head quickly is an important research topic by design professionals in the current, which not only meet the performance requirements, but also guarantee the requirement of reliability. The sub-model method is high efficient and high precision in solving the complex problem of stress and strain, which widely used in truss, road, bridge and large container. Using this technology in the local structure optimization of the cylinder head, will shorten the cycle of structure optimization greatly, and quickly get the optimal design of cylinder head. In this paper, Firstly, the cylinder head global FE model was set up. Considering room assembly and hot firing conditions, the cylinder head stress and strain field was obtained.
2017-10-08
Technical Paper
2017-01-2441
Zhao Ding, Li Chen, Chengliang Yin, Jian Yao, Chunhao Lee, Farzad Samie
Rotating clutch play an important role in automatic transmission (AT), dual-clutch transmission (DCT) and hybrid transmission. Actuator simplification, cost reduction and control effects improvement is very important to improve the competitiveness of a transmission. An alternative concept of electrical motor driven actuation using a wedge mechanism, a wedge clutch, demonstrates potential benefits. This wedge clutch has the characteristics of good mechanical advantage, self-reinforcement, and faster and more precise controllability using electrical motor. In this paper, a new rotating wedge clutch is proposed. It presents a challenge since motor actuator has to be stationary while the clutch piston is rotating. A new mechanism to connect the motor to the wedge piston, including dual-plane bearings and two mechanical ramp linkages, is studied. The design and verification of the physical structure of the actuator are discussed in detail in the paper.
2017-10-08
Technical Paper
2017-01-2450
Chao Xu, Fuyuan Yang, Jinyu Zhang
Power-split is highlighted as the most popular concept for full hybrid electric vehicles (HEV). However, the energy management and design of power-split heavy duty truck under Chinese driving conditions still need to be investigated. In this paper, the parametric design and an equivalent consumption minimization strategy (ECMS) for the power-split heavy duty truck are presented. Besides, the influence of a penalty factor also discussed. Meanwhile, two different methods to search the engine operation point has been proposed. And the simulation shows both fuel consumption can satisfy the second phase fuel consumption standard and the third phase fuel consumption standard which will be implemented in 2020, in the C-WTVC (Chinese-World Transient Vehicle Cycle). Based on ECMS a design for generator motor and traction motor in power-split heavy duty truck has been processed. The fuel consumption has been indicted to decrease, with the motor power increasing.
2017-10-08
Technical Paper
2017-01-2444
Yanzhong Wang, Guanhua Song
High-speed rotating gears are generally lubricated by fuel injection. Lubricating oil is driven by high-speed rotating gear, and some lubricants will be excited into oil mist, so that the gears are in the gas-liquid mixed environment. In this paper, the computational fluid dynamics model of the fuel injection cooling process is established based on the gear heat transfer behavior under the fuel injection condition. The influence of different fuel injection parameters on the liquid-solid two-phase convective heat transfer coefficient is obtained. On this basis, the accurate boundary conditions of gear temperature field calculation are analyzed by studying the heat transfer behavior of high speed gear injection lubrication. The calculation model of gear temperature based on fuel injection lubrication is established, and the temperature field distribution of gear is obtained.
2017-10-08
Technical Paper
2017-01-2457
Rickard Arvidsson, Tomas McKelvey
A two-state forward dynamic programming algorithm is evaluated in a series hybrid drive-train application with the objective to minimize fuel consumption when look-ahead information is available. The states in the new method are battery state-of-charge and engine speed. The new method is compared to one-state dynamic programming optimization methods where the requested generator power is found such that the fuel consumption is minimized and engine speed is given by the optimum power-speed efficiency line. The other method compared is to run the engine at a given operating point where the system efficiency is highest, finding the combination of engine run requests over the drive-cycle that minimizes the fuel consumption. The work has included the engine torque and generator power as control signals and is evaluated in a full vehicle-simulation model based on the Volvo Car Corporation VSIM tool.
2017-10-08
Technical Paper
2017-01-2458
Mohamed Awadallah, Peter Tawadros, Paul Walker, Nong Zhang
Driven by stricter mandatory regulations on fuel economy improvement and emissions reduction, market penetration of electrified vehicles will increase in the next 10 years, among which mild hybrid will become a leading sector in growth. Researchers forecast the sales of mild hybrid vehicles will reach 1.4 million units per year by 2020, and 7 million units by 2024. The high cost of HEVs has somewhat limited their widespread adoption, especially in developing countries. Conversely, it is these countries that would benefit most from the environmental benefits of HEV technology. Compared to a full hybrid, a plug‐in hybrid or an electric vehicle, a mild hybrid system stands out due to its maximum benefit/cost ratio. As part of our ongoing project to develop a mild hybrid system for these markets to improve the drive performance and efficiency. High power density ultra-capacitors are incorporated for fast charging and discharging during the acceleration and other operations.
2017-10-08
Technical Paper
2017-01-2454
Yiqi Jia, Gangfeng Tan, Cenyi Liu, Shengguang Xiong, Zehao Yang, Xingmang Zheng
In these years, the advantages of using phase change material in the thermal management of electric power battery has been wide spread. Because of the thermal conductivity of most phase change material (eg.wax) is low, many researchers choose to add high conductivity materials(such as black lead). However, the solid-liquid change material has large mass, poor flowability and corrosivity. Therefore, it still stays on experiential stage. In this paper, we use pure water as liquid phase change material (PCM), adopts PCM with an reflux device for thermal management. Meanwhile, utilizing the characteristics of pure water which are economical, easy to prepare, light weight, strong liquidity and hardly corrode the battery to explore the feasibility for water as a PCM for battery thermal management system. We use CATIA to build battery model and FloEFD to simulate temperature distribution of battery during its working stage.
2017-10-08
Technical Paper
2017-01-2456
Yun Li, Jing Shang, Shiwu Zhu, Alina Ma, Robin Lyle, Zijian Li, Nannan Wang, Hua Rong
This paper presents an Integrated Power Module (IPM) and an Integrated Power Unit (IPU) which are based on the IGBT double sided cooling technology. The IPU can be used as the motor control inverter in the electric vehicle. And the IPM used in the IPU is packaged with latest 650V/600A trench field-stop IGBT device and double sided bonding and cooling technology. With the double sided bonding, planar bonding is realized which eliminates the traditional wire bonds. Powers cycling capability and long time reliability of the module have been greatly improved. Integrating with the double sided cooling, a large thermal exchanging area of the dies is achieved. Compared with the traditional single sided cooling module, thermal resistance has been reduced by 23% according to the test. Equipped with the active gate driver technology which utilizing the di/dt control and decoupling of turn-on and turn-off processes, power losses of the IPM have been greatly reduced and optimized.
2017-10-08
Technical Paper
2017-01-2349
Sarita Seth, Swamy Maloth, Prashant Kumar, Bhuvenesh Tyagi, Lokesh Kumar, Rajendra Mahapatra, Sarita Garg, Deepak Saxena, R Suresh, SSV Ramakumar
Automobile OEMs are looking for improving fuel economy of their vehicles by reducing weight, rolling resistance and improving engine and transmission efficiency apart from the aerodynamic design. Fuel economy may be improved by using appropriate low viscosity and use of friction reducers (FRs) in the engine oils. The concept of high viscosity index is being used for achieving right viscosity at required operating temperatures. In this paper performance properties of High Viscosity Index engine oils have been compared with conventional VI engine oils. Efforts has been made to check the key differentiation in oil properties and finally into oil performance w.r.t. low temperature fluidity, high temperature high shear viscosity/deposits, friction behavior, oxidation performance in bench tribological /engine/chassis dyno tests. Three candidates of SAE 0W-30 grade oil with ACEA C2/API SN credentials have been chosen using various viscosity modifiers.
2017-10-08
Technical Paper
2017-01-2413
Peter King
A four-chamber Otto-cycle rotary engine, the Szorenyi Rotary Engine, has been developed by the Rotary Engine Development Agency in Melbourne, Australia. The engine has been awarded a US patent. The geometric shape of the engine rotor is a rhombus which deforms as it rotates inside the contour of a mathematically defined stator. The resulting engine design has a four-segment hinged rotor which creates four combustion chambers. Each chamber produces the four phases of the Otto cycle for every rotation of the rotor. The result is an engine which is similar in operation and size to a Wankel engine, but with four times the power density. The Szorenyi engine could be used in all current applications of Wankel and reciprocating engines. The paper follows the development of the Szorenyi engine. It describes the derivation of the mathematical formula of the stator profile and shows that the profile can be varied to optimise the combustion chamber shape and hence engine performance.
2017-10-08
Technical Paper
2017-01-2435
Jian Ji, BoZhou He, Lei Yuan
It is well-known that, compared with automatic transmissions (ATs), continuously variable transmission (CVT) shows advantages in fuel saving due to its continuous shift manner, since this feature enables the engine to operate in the efficiency-optimized region. However, as the AT gear number increases and the ratio gap narrows, this advantage of CVT is challenged. In this paper, a comparative study on fuel economy for a CVT based vehicle and a 9-speed automatic transmission (AT) based vehicle is proposed. The features of CVT and AT are analyzed and ratio control strategies for both the CVT and 9-speed AT based vehicles are designed from the view point of vehicle fuel economy, respectively. For the 9-speed AT, an optimal gear shift map is constructed. With this gear shift map, the optimal gear is selected as vehicle velocity and driving condition vary.
Viewing 91 to 120 of 110594