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Viewing 61 to 90 of 85313
2017-10-08
Technical Paper
2017-01-2390
Hongxue Zhao, Daliang Jing, Yinhui Wang, Shi-jin Shuai, Changle PANG
Abstract In this paper, the impacts of Aromatic and Olefin on the formation of poly-aromatic hydrocarbons (PAHs) in the gasoline direct injection (GDI) engine were 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 aromatics (A1-A4). In order to better understand the effects of the fuel properties on the formations of PAHs. Three types of fuels, namely base gasoline, gasoline with higher aromatics content, and gasoline with higher olefin content were experimentally studied. At the same time, these aspects were also numerically investigated in the CHEMKIN code by using premixed laminar flame model and surrogated fuels. The results show that higher aromatics content in gasoline will lead to much higher PAHs formation. Similar trend was also found in the gasoline with higher olefin content.
2017-10-08
Technical Paper
2017-01-2387
Yonge Wu, Xingyu Liang, Ge-Qun Shu, Boxi Shen, Yuesen Wang, Xikai Liu, Zhijun Li
Abstract Currently, selective catalytic reduction (SCR) is one of the main after-treatment systems to control diesel engine NOx emission. But the SCR system is bulky, considering the limited installation space. Therefore, the design of SCR system with the compact structure and reliable performance is one of the essential topics. In this study, the structure parameters, such as catalyst cross-sectional area, catalyst length, substrate wall thickness, coating thickness, channels per square inch (CPSI) of substrate, are taken into consideration to study their effects on the SCR performance and narrow the scope of various structural parameters for the following optimization study. Then, the structural parameters of the SCR reactor are optimized by considering the coupling relationship among these structural parameters by using the Response Surface Methodology (RSM) at high load of diesel engine.
2017-10-08
Technical Paper
2017-01-2408
Lei Zhou, Hongxing Zhang, Zhenfeng Zhao, Fujun Zhang
Abstract The Opposed Piston Two-Stroke (OPTS) engine has many advantages on power density, fuel tolerance, fuel flexibility and package space. A type of self-balanced opposed-piston folded-crank train two-stroke engine for Unmanned Aerial Vehicle (UAV) was studied in this paper. AVL BOOST was used for the thermodynamic simulation. It was a quasi-steady, filling-and-emptying flow analysis -- no intake or exhaust dynamics were simulated. The results were validated against experimental data. The effects of high altitude environment on engine performance have been investigated. Moreover, the matching between the engine and turbocharger was designed and optimized for different altitude levels. The results indicated that, while the altitude is above 6000m, a multi-stage turbocharged engine system need to be considered and optimized for the UAV.
2017-10-08
Technical Paper
2017-01-2404
Douglas Ball, David Lewis, David Moser, Sanket Nipunage
Abstract Federal Test Procedure (FTP) emissions were measured on a 2009 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 underfloor converters. Base CARB PH-III certification fuel was used. Three consecutive FTPs were used to measure the impact of fuel sulfur and catalyst PGM loading combinations. In general, reducing fuel sulfur and increasing catalyst PGM loadings, decrease FTP emissions. Increasing Pd concentrations can mitigate the impact of higher fuel sulfur concentrations. The results also suggest that a 50% reduction in PGM can be achieved with a reduction in fuel sulfur from 30 to 10 ppm. On average, NMHC, CO and NOx emissions were reduced by 12, 49 and 64%, respectively with the 10 ppm sulfur fuel. In addition, HC and NOx vehicle emission variability were reduced by 74 and 57% with the 10 ppm sulfur fuel.
2017-10-08
Technical Paper
2017-01-2405
Christophe Chaillou, Alexandre Bouet, Arnaud Frobert, Florence Duffour
Abstract Fuels from crude oil are the main energy vector used in the worldwide transport sector. But conventional fuel and engine technologies are often criticized, especially Diesel engines with the recent “Diesel gate”. Engine and fuel co-research is one of the main leverage to reduce both CO2 footprint and criteria pollutants in the transport sector. Compression ignition engines with gasoline-like fuels are a promising way for both NOx and particulate emissions abatement while keeping lower tailpipe CO2 emissions from both combustion process, physical and chemical properties of the low RON gasoline. To introduce a new fuel/engine technology, investigation of pollutants and After-Treatment Systems (ATS) is mandatory. Previous work [1] already studied soot behavior to define the rules for the design of the Diesel Particulate Filter (DPF) when used with a low RON gasoline in a compression ignition engine.
2017-10-08
Technical Paper
2017-01-2406
Wu Yang, Xiuting Yin, Zhang Song Zhan, Huixian Shen, Huibin Qing, Qingqiang Zeng, Liyun Kang
Abstract This work addresses the problem of fatigue strength prediction of crankshaft fillet rolling processes to improve its accuracy. It is empirical to usually consider the effect of fillet rolling process on crankshaft fatigue performance. The fatigue performance of rolling process is mainly determined by induced compressive residual stresses, increased hardness and reduced roughness. Because the first two factors are difficult to measure the arc surface of fillet rolled cranks, it is difficult to predict the enhanced rate of crankshaft rolled performance to baseline unrolled’s. In this work a prediction method of fatigue strength for ductile cast iron crankshafts rolling process is presented. This method indirectly predicts the effect of the increased hardness on fatigue performance by the resonant bending fatigue test and modelling of crankshaft fillet rolling dynamic for the induced compressive residual stress.
2017-10-08
Technical Paper
2017-01-2407
Michael Bardon, Greg Pucher, David Gardiner, Javier Ariztegui, Roger Cracknell, Heather Hamje, Leonardo Pellegrini, David Rickeard
Abstract 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. Gasoline is much more volatile than diesel so, at most ambient temperatures, the headspace vapours in the tank are too rich to burn. A gasoline/diesel mixture in a fuel tank therefore can result in a flammable headspace, particularly at cold ambient temperatures. 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.
2017-10-08
Technical Paper
2017-01-2401
Elana Chapman, Pat Geng, Yaowei Zhao, Susan Zhang, JunJun Ma, Jianqiang Gong
Abstract The impact of gasoline composition on vehicle particulate emissions response has been widely investigated and documented. Correlation equations between fuel composition and particulate emissions have also been documented, e.g. Particulate Matter Index (PMI) and Particulate Evaluation Index (PEI). Vehicle PM/PN emissions correlate very well with these indices. In a previous paper, global assessment with PEI on fuel sooting tendency was presented [1]. This paper will continue the previous theme by the authors, and cover China gasoline in more detail. With air pollution an increasing concern, along with more stringent emission requirements in China, both OEMs and oil industries are facing new challenges. Emissions controls require a systematic approach on both fuels and vehicles. Chinese production vehicle particulate emissions for a range of PEI fuels are also presented.
2017-10-08
Technical Paper
2017-01-2403
Yanzhao An, R Vallinayagam, S Vedharaj, Jean-Baptiste Masurier, Alaaeldin Dawood, Mohammad Izadi Najafabadi, Bart Somers, Bengt Johansson
Abstract In-cylinder visualization, combustion stratification, and engine-out particulate matter (PM) emissions were investigated in an optical engine fueled with Haltermann straight-run naphtha fuel and corresponding surrogate fuel. The combustion mode was transited from homogeneous charge compression ignition (HCCI) to conventional compression ignition (CI) via partially premixed combustion (PPC). Single injection strategy with the change of start of injection (SOI) from early to late injections was employed. The high-speed color camera was used to capture the in-cylinder combustion images. The combustion stratification was analyzed based on the natural luminosity of the combustion images. The regulated emission of unburned hydrocarbon (UHC), carbon monoxide (CO) and nitrogen oxides (NOX) were measured to evaluate the combustion efficiency together with the in-cylinder rate of heat release.
2017-10-08
Technical Paper
2017-01-2402
Yoshinori Otsuki, Shigemi Tochino, Kenji Kondo, Kazuhiko Haruta
Abstract Fine particle emissions from engine exhaust have attracted attention because of concern of their higher deposition fraction in alveoli. Since it was observed that sizes of solid particles in exhaust of conventional internal combustion engine technologies are mainly distributed above 30 nm and the mainly irreproducible sensitivity to volatile particles can be reduced, the current solid particle number (PN) measurement methodology was targeted to PN emissions particles larger than 23 nm. The necessity of the measurement of particles smaller than 23 nm is now under discussion. It is also surmised that there is difference between emissions under regulatory defined test cycles and real driving conditions. Currently, implementation of further real driving emission regulations utilizing portable emissions measurement systems (PEMS) is in place for the EU and being actively discussed in other regions.
2017-10-08
Technical Paper
2017-01-2413
Peter King
Abstract A four-chamber Otto cycle rotary engine, the Szorenyi Rotary Engine, has been invented and developed by the Rotary Engine Development Agency (REDA) in Melbourne, Australia. The engine concept has been awarded a U.S. Patent (Number 6,718,938 B2). A prototype engine has been constructed and a successful proof-of-concept engine test was achieved in 2008. The stator of the Szorenyi engine is a similar shape to a Wankel engine. However, the geometric shape of the engine rotor is a rhombus, which deforms as it rotates inside the contour of the mathematically defined stator. This geometry translates to a rotary engine with four combustion chambers. Each revolution of the crankshaft produces one revolution of the rotor; a complete engine cycle in each of the four chambers; and therefore four power strokes. In contrast, the Wankel engine produces one power stroke per crankshaft revolution.
2017-10-08
Technical Paper
2017-01-2412
Dojoong Kim, Dong Hyeong Lee, Jong Wung Park, Soo Hyun Hwang, Wan Jae Jeon
Abstract This paper introduces a two-step variable valve actuation (VVA) mechanism equipped with an electronic switching system, which can be applied to OHC valve trains with end pivot rocker arms. The electronic switching system is driven by a dedicated solenoid and is not affected by the temperature or pressure of the engine oil. Therefore, not only can the dynamic stability be secured at the time of mode switching but the operation delay time can also be kept short enough. Several models of two-step VVA mechanisms were fabricated and the operability of the mechanism and switching system was experimentally confirmed. The two-step VVA mechanism developed in this study can also be used as a cylinder deactivation (CDA) system by assigning the lift of the low-speed cam to be zero. By attaching a roller to the portion of the rocker arm that is in contact with the base cam, the problem of pad wear, which is often present in CDA mechanism, is also fundamentally solved.
2017-10-08
Technical Paper
2017-01-2414
Dongsheng Zhang, Qilong Lu, Michael Kocsis, Ian Gilbert, Marc Megel, Xihao Liu, Jiaxin Gu, Qingyan Liu, Yanming He
Abstract The new Beijing Automotive Industry Corporation (BAIC) engine, an evolution of the 2.3L 4-cylinder turbocharged gasoline engine from Saab, was designed, built, and tested with close collaboration between BAIC Motor Powertrain Co., Ltd. and Southwest Research Institute (SwRI®). The upgraded engine was intended to achieve low fuel consumption and a good balance of high performance and compliance with Euro 6 emissions regulations. Low fuel consumption was achieved primarily through utilizing cooled low pressure loop exhaust gas recirculation (LPL-EGR) and dual independent cam phasers. Cooled LPL-EGR helped suppress engine knock and consequently allowed for increased compression ratio and improved thermal efficiency of the new engine. Dual independent cam phasers reduced engine pumping losses and helped increase low-speed torque. Additionally, the intake and exhaust systems were improved along with optimization of the combustion chamber design.
2017-10-08
Technical Paper
2017-01-2415
Valery Dunaevsky
Abstract The film thickness-roughness ratio Λ has been used since the mid-1960s as a simplified criterion for the lubrication conditions in rolling bearings. However, due to an assumed Gaussian distribution of the roughness height amplitudes of the functional surfaces of rolling bearings and other unsubstantiated assumptions regarding the mechanisms of contact interaction, concerns have arisen about the representability of Λ in terms of lubrication. In this study, a more objective Λ-type ratio that does not depend on the law of roughness height distribution and the peculiarities of contact mechanics is introduced and defined as Λz. The relevant range of the new Λ ratio is lower than that of its conventional counterpart, and it overlaps with contemporary theoretical and experimental results. The study exhibits unique profilometric data of the functional surfaces of the roller bearings, produced by the major bearing manufacturers.
2017-10-08
Technical Paper
2017-01-2409
Erbao Zhang, Yinchun Gong, Jun Deng, Zongjie Hu, Chuanqian Jiang, Zhijun Wu, Liguang Li
Abstract The work of this paper aimed at investigating the cyclic variations of argon power cycle engine with fuel of hydrogen at lean burn operating conditions. The engine had been modified based on a 0.402 L, single-cylinder diesel engine into spark ignition engine with a port fuel injection system. The influencing factors on the cyclic variations, such as ignition timing, engine speed and compression ratio, were tested in this study. In all tests, the throttle opened at 0%, and the excess oxygen coefficient was maintained at 2.3. The results showed that as the ignition timing retards, CoVPmax and CoV(dp/dφ)max of argon power cycle engine increased, while CoVIMEP decreased firstly and increased afterward. And there is an ignition timing to make the lowest CoVIMEP, which is not consistent with MBT.
2017-10-08
Technical Paper
2017-01-2411
Henry Guo, Wenchuan Jia, DeDong Xie
Abstract 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
2017-01-2410
Ji Gao, Tie Wang, Dandan Sun, Jing Qiao, Yizhuo Feng
Abstract As the explosion proof diesel engine (EPD) of underground trackless tyred vehicle dynamic mechanical device, due to its good dynamic and economic performance, the diesel has been widely applied. The flame arrester can prevent the exhaust system from tempering, but the increased resistance will seriously affect the performance of diesel. Through the comparison of the CFD-FLUENT fluid simulation on flow and pressure field, the results show that the corrugated flame arrester performs better on reducing the exhaust back pressure than flat flame arrester and ensures the explosion-proof effect. The bench test of explosion proof diesel engine on intake and exhaust system is conducted, analysing the effect of the exhaust resistance under different speeds of diesel engine on the power, economy and emission of TY4100QFB type diesel engines with equivalent flow area , different specifications of flat versus corrugated flame-arrester in the course of external characteristics.
2017-10-08
Technical Paper
2017-01-2430
Yingmin Wang, Tao Cui, Fujun Zhang, Sufei Wang, Hongli Gao
Abstract Considering the randomness and instability of the oil pressure in the lubrication system, a new approach for fault detection and diagnosis of diesel engine lubrication system based on support vector machine optimized by particle swarm optimization (PSO-SVM) model and centroid location algorithm has been proposed. Firstly, PSO algorithm is chosen to determine the optimum parameters of SVM, to avoid the blindness of choosing parameters. It can improve the prediction accuracy of the model. The results show that the classify accuracy of PSO-SVM is improved compared with SVM in which parameters are set according to experience. Then, the support vector machine classification interface is fitted to a curve, and the boundary conditions of fault diagnosis are obtained. Finally, diagnose algorithm is achieved through analyzing the centroid movement of features. According to Performance degradation data, degenerate trajectory model is established based on centroid location.
2017-10-08
Technical Paper
2017-01-2432
Xiangwang Li, Weimin Wang, Xiongcai Zou, Zhiming Zhang, Wenlong Zhang, Shemin Zhang, Tao Chen, Yuhuang Cao, Yuanda Chen
Abstract In order to reduce emissions, size and manufacturing cost, integrated exhaust manifold become popular in gasoline engine, especially in three-cylinder engine. Moreover, due to shorter length, lighter weight, and less component connections, the exhaust manifold and hot end durability will improve apparently. In this work, an advanced cylinder head with integrated exhaust manifold is adopted in a three-cylinder turbo engine. Because of this integration characteristic, the gas retain in cylinder head longer and the temperature reach higher level than normal cylinder head, which will cause thermal fatigue failure more easily. To validate the exhaust manifold and hot end durability, series simulation and test validation work have been done. Firstly, overall steady state and transient temperature simulation was done for global model. For turbocharger, in order to simulate the outlet turbulent flow and 3d rotation, a code was compiled to define this 3d rotation.
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
Abstract Nowadays high thermal efficiency engine is the mainstream of the gasoline engine development, and the control of the design period is strict, 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 meets the performance requirements, but also guarantees 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 significantly, and get the optimal design of cylinder head quickly. In this paper, Firstly, the cylinder head global FE model was set up.
2017-10-08
Technical Paper
2017-01-2426
Zhiming Zhang, Weimin Wang, Jiangtao Wang, Jiming Zhang, Yuanda Chen, Wenlong Zhang, Guofang Yang, Fugui Fan, Wenxiang Zhang, Fengqin Huang, Xiangwang Li
Abstract In recent years, Turbo-charged GDI technology is more and more widely used, which can meet the high demand of the engine performance and efficiency, but the resulting reliability and NVH issues also need to be paid attention to [1]. Traditional NVH performance improvement is mostly based on the experience design and repeatable test, which lead to longer development period, high cost, and also ineffective results. NVH performance simulations play more important role in engine vibration and noise prediction along with the development of the simulation technology[2][3]. The force response analysis is usually used to evaluate the NVH performance of the engine structure under the standard excitation. However, dynamic analysis of the crank train, valve train, and piston can be carried out based on the AVL software family, also the vibration and airborne noise of whole engine can be predicted directly at different speed and load [4].
2017-10-08
Technical Paper
2017-01-2428
Peilin Dai, Ying Huang, Donghao Hao, Ting Zhang
Abstract The vehicle driveline suffers low frequency torsional vibration due to the abrupt change of input torque and torque fluctuation under variable frequency. This problem can be solved by model based control, so building a control oriented driveline model is extremely important. In this paper, an on-line recursive identification method is proposed for control oriented model and validated based on an electric car. First of all, the control oriented driveline model is simplified into a six-parameter model with double inertia. Secondly, based on stability analysis, motor torque and motor speed are chosen as input signal for on-line model identification. A recursive identification algorithm is designed and implemented based on Simulink. Meanwhile a detail model of the vehicle which considering driveline parameter variation is built based on ADAMS. Thirdly, on-line identification is conducted by using co-simulation of ADAMS and Simulink.
2017-10-08
Technical Paper
2017-01-2429
Felix Leach, Martin Davy, Adam Weall, Brian Cooper
Abstract Diesel engine designers often use swirl flaps to increase air motion in cylinder at low engine speeds, where lower piston velocities reduce natural in-cylinder swirl. Such in-cylinder motion reduces smoke and CO emissions by improved fuel-air mixing. However, swirl flaps, acting like a throttle on a gasoline engine, create an additional pressure drop in the inlet manifold and thereby increase pumping work and fuel consumption. In addition, by increasing the fuel-air mixing in cylinder the combustion duration is shortened and the combustion temperature is increased; this has the effect of increasing NOx emissions. Typically, EGR rates are correspondingly increased to mitigate this effect. Late inlet valve closure, which reduces an engine’s effective compression ratio, has been shown to provide an alternative method of reducing NOx emissions.
2017-10-08
Technical Paper
2017-01-2422
Na Li, Fenlian Huang, Yuhua Bi, Yueqiang Xu, Lizhong Shen, Dewen Jia
Abstract The assembly of con rod bearing and crankpin is a key friction pair which offers an important guarantee for stable operation of diesel engine. Specific to the non-road 2-cylinder diesel engine developed independently and based on the theory of thermoelastohydrodynamic lubrication as well as multi-body dynamics, this paper establishes a multi-body dynamics model for con rod big end bearings of the 2D25 horizontal diesel engine and makes a research on the influence of bearing width, bearing clearance, and oil inlet position and diameter upon lubrication of con rod bearing, taking into consideration that of the surface appearance of bearing bush and the elastic deformation of bearing bush and axle journal upon the same. Research results show that bearing width and bearing clearance are the major factors that influence lubrication characteristics of con rod bearing while oil inlet position and diameter only have a small influence on such characteristics.
2017-10-08
Technical Paper
2017-01-2423
Xiaoming Ye, Yan Fu, Wei Li, Yuze Jiang, Shixin Zhu
Abstract 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
2017-01-2425
Ramit Verma, Ramdas R Ugale
Abstract On two wheelers, magneto/alternator generates either single/three phase AC power and Regulator Rectifier Unit (RRU) does regulated rectification to charge the battery. In order to face the requirements of 2-wheeler engine with respect to upcoming stringent regulations like electronic fuel injection (EFI), anti-lock braking system (ABS), automatic headlamp on (AHO) in emerging markets like India; vehicles demand more electrical power from batteries. This demands higher power from alternator and consequently from RRU. Requirement of higher output power presents challenges on regulator rectifier unit in terms of size, power dissipation management and reliability. In this paper, improved performance of MOSFET based RRU is discussed in comparison to Silicon Controlled Rectifier (SCR) based RRU. The motivation/benefits of MOSFET based design is described along with the thermal behavior and temperature coefficient performance of RRU with test results.
2017-10-08
Technical Paper
2017-01-2417
Houchuan Fan, Jimin Ni, Xiuyong Shi, Nan Jiang, Dayong Qu, Yi Zheng, Yinghong Zheng
Abstract An electronic waste-gated turbocharger for automotive application can accurately control the boost pressure and effectively reduce turbo-lag. It can improve the transient responsive performance of engine and the acceleration performance of vehicle, which makes vehicle have a better adaptation to the complex traffic environment. A detailed analysis of aerodynamic working principle of electronic wastegate is the foundation for designing the control strategy of electronic wastegate. Putting turbine with electronic wastegate under unsteady condition that simulates the pulse exhaust gas of engine and studying influences of different valve opening on the performance of turbine has the practical value. This paper sets fixed and periodical unsteady conditions and adopts numerical methods to explore the performance of turbine in twin-entry turbocharger and the flow loss of bypass. Steady simulation structure is given for reference.
2017-10-08
Technical Paper
2017-01-2418
Hong Zhang, Zhuo Wang, Zhouzhensen Hong
Abstract The electric compound turbocharger(ECT) which integrates a high speed motor into a turbocharger rotor shaft can be used transiently to accelerate the turbocharger more quickly in response to an acceleration requirement. It can utilize the exhaust gas energy fully to improve the engine fuel efficiency and benefit for engine with lower emissions. The key technique of ECT is to solve the reliability problems when an electrical motor is integrated into a turbocharger shaft between the turbine and compressor wheels will increase the burden for the bearing support and affect the turbocharger shaft rotation characteristics. In order to know the dynamics behavior of higher load bearing system is explored for reliability, this paper focus on the nonlinear rotor dynamics characteristics of ECT rotor bearing system.
2017-10-08
Technical Paper
2017-01-2420
Bertrand Kerres, Andreas Cronhjort, Mihai Mihaescu, Ola Stenlaas
Abstract On-engine surge detection could help in reducing the safety margin towards surge, thus allowing higher boost pressures and ultimately low-end torque. In this paper, experimental data from a truck turbocharger compressor mounted on the engine is investigated. A short period of compressor surge is provoked through a sudden, large drop in engine load. The compressor housing is equipped with knock accelerometers. Different signal treatments are evaluated for their suitability with respect to on-engine surge detection: the signal root mean square, the power spectral density in the surge frequency band, the recently proposed Hurst exponent, and a closely related concept optimized to detect changes in the underlying scaling behavior of the signal. For validation purposes, a judgement by the test cell operator by visual observation of the air filter vibrations and audible noises, as well as inlet temperature increase, are also used to diagnose surge.
2017-10-08
Technical Paper
2017-01-2421
Dongkang Cheng, Xiaori Liu
Abstract 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. The results show that: The temperature of cylinder liner has obviously influence on the oil film temperature, while the temperature of piston rings has little influence.
Viewing 61 to 90 of 85313