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Viewing 211 to 240 of 85301
2017-10-08
Technical Paper
2017-01-2398
Bei Liu, Xiaobei Cheng, Jialu Liu, Han Pu, Li Yi
Abstract Partially-premixed low-temperature combustion avoids the soot and NOx generation area on the Ф-T diagram to reduce both engine NOx and soot emissions. Compared with the HCCI combustion mode, partially-premixed combustion (PPC) has better combustion controllability. The purpose of controlling the combustion phase can be achieved by adjusting injection timing and strategy. Based on a 4 cylinder turbocharged diesel engine, this paper aims at investigating the influence of injection strategy to the engine combustion and emission formation under the condition of single injection and split injection PPC strategy respectively, in which the primary purpose focus on the emission characteristics of particles. Results show that the early-injection PPC formed by single injection can reduce the quantity, quality and geometric mean diameter (GMD) of particles obviously.
2017-10-08
Technical Paper
2017-01-2396
Fushui Liu, Yang Hua, Han Wu, Xu He, Ning Kang
Abstract Soot emission, known as PM (particulate matter), is becoming a big issue for GDI engines as the emission regulations being increasingly stricter. It is found that ethanol, as an oxygenated bio-fuel, can reduce the soot emission when added to gasoline. In order to fully understand the effect of ethanol on soot reducing, the soot characteristics of ethanol/gasoline blends were studied on laminar diffusion flames. In this experiment, the blending ratio of ethanol/gasoline was set as E0/20/40/60/80. Considering the carbon content decreasing due to ethanol addition, carbon mass flow rate was remained constant. The two-dimensional distributions of soot volume fraction were measured quantitatively by using two-color laser induced incandescence technique. The results showed that ethanol is able to decrease the soot significantly, but the effect of ethanol on soot reduction is weakened with the increasing ethanol ratio.
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
2017-01-2399
Jianyu Duan, Kai Sun, Lei Li
Abstract Particulate matter emissions have become a concern for the development of DISI engines. EGR has been extensively demonstrated as a beneficial technology to migrate knock performance, improve fuel economy and reduce NOX emissions. Recently, the effect of EGR on particulate matter emissions is attracting increased attention. This work investigates the effects of EGR on PN emissions with the variations of engine operating parameters and aims to understand the role of EGR in PN emissions for DISI engines. A 1.8liter turbocharged engine with cooled EGR is used for this study. The engine is operated at steady-state conditions with EGR under various operating parameters including injection timing, excess air ratio, and spark timing to characterize the particle number emissions. The results indicates that there is a high sensitivity of PN emissions to EGR with the variations of those parameters.
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
2017-01-2403
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
2017-01-2415
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
Journal Article
2017-01-2446
Pengchuan Wang, Nikolaos Katopodes, Yuji Fujii
Wet clutch packs are the key component for gear shifting in the step-ratio automatic transmission system. They are coupled or de-coupled to alter gear ratios based on driver’s demand and vehicle operating conditions. The frictional interfaces between clutch plates are lubricated with automatic transmission fluid (ATF) for both thermal and friction management. In a 10-speed transmission, there may be as many as 6 clutch packs. Under any driving conditions, 2 to 3 clutch packs are typically open, shearing ATF and contributing to energy loss. There is an opportunity to improve fuel economy by reducing this viscous drag. One main factor that directly affects clutch drag is the clearance between rotating plates. The axial position of clutch plates changes continually at every instance. It is empirically known that not only the total clearance, but also its distribution between the plates affects the viscous drag.
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
2017-01-2452
Kingsley Joel Berry, Abdrahamane Traore, Aravind Krishna, Pavankumar Gangadhar, Allan Taylor
This paper documents the electrical infrastructure design of a Hybrid Go Kart competition vehicle which includes a dual Fuel Cell power system, Ultra Capacitors for energy storage, and a dual AC induction motor capable of independent drive. The Kart was built primarily to compete in the 2009 Formula Zero international event. The vehicle model was developed in Simulink to determine whether the fuel cell and ultra-capacitor combination will be sufficient for peak transient power requirement of 36 kW. The vehicle’s functional description and performance specifications are documented including the integration of the fuel cell power modules, energy storage system, power converters, and AC motor and motor controllers.
2017-10-08
Technical Paper
2017-01-2453
Shuang Liu, Lina Pan, Xin Jiang, Yujiao Wang, Kun Liu, Yang Xia
Quick drop battery system was the core components of the electric vehicles, the reliability and compatibility of quick drop battery system was directly related to the popularization and application of electric vehicles. In this article, a split type battery management system and a split type high voltage architecture is used to achieve better charging compatibility. Meanwhile the number of fast switching connector’s pin is reduced and the plug life is prolonged to more than 10000 times by using floating structure. For battery management system (BMS), the state of charge (SOC) estimation was based on dynamic voltage correction, and make estimation accuracy reach to less than 5%. Rotary slot limit and fast locking mechanism had been designed for the first time and the precision of battery system assembling could control within 3mm, hence the floating structure’s damage could be reduced and the mechanical life could be enhanced.
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
2017-01-2457
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
Journal Article
2017-01-2459
Liu Xiaojun, Yu Jinpeng, Yang Xia, Wu Daoming, Jie Zhu
In the case of electric vehicles, due to the charging current limitation of lithium battery at low temperatures (below -20℃), it has been proposed to heat the battery pack up to a suitable temperature range before charging through a liquid-heating plate with PTC. However, in the low state of charge (SOC), there is a question which one could take the place of battery pack to supply power for PTC when heating. So that off-board charger has been considered to supply power for PTC detailed in this paper. In order to control the current charging to the battery pack as less as possible at low temperatures, three control strategy models are established and compared: First, BMS controls the charging request current value which is send to off-board charger as a signal, and equals to the working current of PTC. Second, BMS controls the charging request voltage value which is slightly lower than the battery pack voltage.
2017-10-08
Technical Paper
2017-01-2460
Wenbin Liu, Qiang Song, Yiting Li, Wanbang Zhao
In this paper, a novel driver model is proposed to track vehicle speed in MIL (Model-in-the-Loop) test system, which has structural consistency with HIL (Hardware-in-the-Loop) test system. First, the MIL test system which contains models of driver, vehicle and test bench is established. Second, according to the connections of the established models in Matlab/Simulink environment, the vehicle speed is calculated in vehicle model. Emphatically, through the deviation between driving cycle speed and calculated vehicle speed, PI controller in driver model adjusts the vehicle speed to ideal point through sending the torque command to drive motor, the ILC (Iterative Learning Control) controller modifies and stores P value of PI controller. Then, in order to obtain the better modification of PI controller, iterative learning control algorithm is deeply researched in term of types and parameters.
2017-10-08
Technical Paper
2017-01-2462
Ruipeng Zhang, Kaichuang Meng
The powertrain of the separated axle hybrid electric dump truck was analyzed, and the vehicle dynamics model was established. Considering the switch among different drive modes during the process of driving, a driving force coordinated allocation control strategy was applied. The control strategy adopts hierarchical structure, the upper layer determines power take-off mode of the vehicle, the middle layer calculates the drive torque of each axle according to its axle load, the lower layer uses PID algorithm to avoid the slip of the drive axle. Control model is established according to the control strategy, combined with the established vehicle dynamic model, co-simulation was conducted. The simulation results show that the driving force coordinated control strategy can adapt to the full load climbing condition and low adhesion road condition, realize the reasonable distribution of driving force and make full use of the ground adhesion.
2017-10-08
Technical Paper
2017-01-2182
Xikai Liu, Xingyu Liang, Yonge Wu, Yuesen Wang
Abstract According to the study of the soot emission in the combustion of diesel,a new reduced mechanism for n-Heptane was constructed to describe the combustion process in diesel engine by using sensitivity analysis.Furthermore,verifying the ignition delay time in combustion process by using CHEMKIN PRO in different pressure of 13.5 atm and 42 atm, initial temperatures of 600k and equivalence ratio of 0.5 and 1.0.Then,compare the simulated results with the experiment data, the mechanisms used in the simulation were Lawrence Livermore National Laboratory (LLNL) detail mechanism and the State Key Laboratory of Engine (SKLE) mechanism.
2017-10-08
Technical Paper
2017-01-2185
Chao He, Jiaqiang Li, Longqing Zhao, Yanyan Wang, Wei Gu
Abstract More and more stringent emission regulations and the desire to reduce fuel consumption lead to an increasing demand for precise and close-loop combustion control of diesel engines. Cylinder pressure-based combustion control is gradually used for diesel engines in order to enhance emission robustness and reduce fuel consumption. However, it increases the cost. In this paper, a new prediction method of combustion parameters is presented for diesel engines. The experiment was carried out on a test bench to obtain the ECU (Electronic Control Unit) signals of a heavy-duty diesel engine by calibration software. The combustion parameters was measured by a combustion analyzer, such as maximum cylinder pressure (MCP), maximum combustion temperature (MCT), and combustion center of gravity (CA50). A combustion model using genetic programming (GP) is built. The input parameters are chosen from the ECU signals, such as engine speed, engine load, injection quantities, inlet air flow rate.
2017-10-08
Technical Paper
2017-01-2186
Lukas Urban, Michael Grill, Sebastian Hann, Michael Bargende
Abstract Engine Knock is a stochastic phenomenon that occurs during the regular combustion of spark ignition (SI) engines and limits its efficiency. Knock is triggered by an autoignition of local “hot spots” in the unburned zone, ahead of the flame front. Regarding chemical kinetics, the temperature and pressure history as well as the knock resistance of the fuel are the main driver for the autoignition process. In this paper, a new knock modeling approach for natural gas blends is presented. It is based on a kinetic fit for the ignition delay times that has been derived from chemical kinetics simulations. The knock model is coupled with an enhanced burn rate model that was modified for Methane-based fuels. The two newly developed models are incorporated in a predictive 0D/1D simulation tool that provides a cost-effective method for the development of natural gas powered SI engines.
2017-10-08
Technical Paper
2017-01-2188
Bruno S. Soriano, Edward S. Richardson, Stephanie Schlatter, Yuri M. Wright
Abstract Dual-fuel combustion is an attractive approach for utilizing alternative fuels such as natural gas in compression-ignition internal combustion engines. In this approach, pilot injection of a more reactive fuel provides a source of ignition for the premixed natural gas/air. The overall performance combines the high efficiency of a compression-ignition engine with the relatively low emissions associated with natural gas. However the combustion phenomena occurring in dual-fuel engines present a challenge for existing turbulent combustion models because, following ignition, flame propagates through a partially-reacted and inhomogeneous mixture of the two fuels. The objective of this study is to test a new modelling formulation that combines the ability of the Conditional Moment Closure (CMC) approach to describe autoignition of fuel sprays with the ability of the G-equation approach to describe the subsequent flame propagation.
2017-10-08
Journal Article
2017-01-2436
Santosh Deshmane, Onkar Gangvekar, Samson Rajakumar
Abstract In today’s competitive automobile market, driver comfort is at utmost importance and the bar is being raised continuously. Gear Shifting is a crucial customer touch point. Any issue or inconvenience caused while shifting gear can result into customer dissatisfaction and will impact the brand image. While there are continual efforts being taken by most of the car manufactures, “Double Bump” in gearshift has remained as a pain area and impact severely on the shift feel. This is more prominent in North-South (N-S) transmissions. In this paper ‘Double Bump’ is a focus area and a mathematical / analytical approach is demonstrated by analyzing ‘impacting parameters’ and establishing their co-relation with double bump. Additionally, the results are also verified with a simulation model.
2017-10-08
Journal Article
2017-01-2445
Santosh Deshmane, Onkar P. Gurav, Vipul Sahu
Abstract Today’s automotive industry is facing cutthroat competition, especially in passenger vehicle business. Manufacturers around the globe are developing innovative and new products keeping focus on end customer; thus customer's opinion and perception about the product has become a factor of prime importance. Customer touch points such as gear shift lever, clutch, brakes, steering etc. are thus gaining more and more importance. Car companies are trying to induce more and more luxuries in these touch points so that they impress customer and create a positive opinion about the product. On the other hand manufacturers are also trying to manage profits. Companies thus need to find the best fit solution for improvising customer touch points with optimized costs. The performance of these touch points is driven by subsystems of mechanical components like mechanical linkage.
2017-10-08
Technical Paper
2017-01-2184
Vincenzo De Bellis, Fabio Bozza, Daniela Tufano
Abstract Nowadays, the development of a new engine is becoming more and more complex due to conflicting factors regarding technical, environmental and economic issues. The experimental activity has to comply with the above complexities, resulting in increasing cost and duration of engine development. For this reason, the simulation is becoming even more prominent, thanks to its lower financial burden, together with the need of an improved predictive capability. Among the other numerical approaches, the 1D models represent a proper compromise between reliability and computational effort, especially if the engine behavior has to be investigated over a number of operating conditions. The combustion model has a key role in this contest and the research of consistent approaches is still on going. In this paper, two well-assessed combustion models for Spark Ignition (SI) engines are described and compared: the eddy burn-up theory and the fractal approach.
2017-10-08
Technical Paper
2017-01-2191
Yachao Chang, Ming Jia, Yanzhi Zhang, Yaopeng Li, Weiwei Fan, MaoZhao Xie
Abstract Dimethyl ether (DME) attracts increasing attentions in recent years, because it can reduce the carbon monoxide (CO), unburned hydrocarbon (HC), and soot emissions for engines as the transportation fuel or the fuel additive. In this paper, a reduced DME oxidation mechanism is developed using the decoupling methodology. The rate constants of the fuel-related reactions are optimized using the non-dominated sorting genetic algorithm II (NSGA-II) to reproduce the ignition delay times in shock tubes and major species concentrations in jet-stirred reactors (JSR) over low-to-high temperatures. In NSGA-II, the range of the rate constants was considered to ensure the reliability of the optimized mechanism. Moreover, an improved objective function was proposed to maintain the faithfulness of the optimized mechanism to the original reaction mechanism, and a new method was presented to determine the optimal solution from the Pareto front.
2017-10-08
Technical Paper
2017-01-2190
Alessandro D'Adamo, Marco Del Pecchia, Sebastiano Breda, Fabio Berni, Stefano Fontanesi, Jens Prager
Abstract CFD simulations of reacting flows are fundamental investigation tools used to predict combustion behaviour and pollutants formation in modern internal combustion engines. Focusing on spark-ignited units, most of the flamelet-based combustion models adopted in current simulations use the fuel/air/residual laminar flame propagation speed as a background to predict the turbulent flame speed. This, in turn, is a fundamental requirement to model the effective burn rate. A consolidated approach in engine combustion simulations relies on the adoption of empirical correlations for laminar flame speed, which are derived from fitting of combustion experiments. However, these last are conducted at pressure and temperature ranges largely different from those encountered in engines: for this reason, correlation extrapolation at engine conditions is inevitably accepted. As a consequence, relevant differences between proposed correlations emerge even for the same fuel and conditions.
2017-10-08
Technical Paper
2017-01-2192
Shenghui Zhong, Zhijun Peng, Yu Li, Hailin Li, Fan Zhang
Abstract A 3-D DNS (Three-Dimensional Direct Numerical Simulation) study with detailed chemical kinetic mechanism of methane has been performed to investigate the characteristics of turbulent premixed oxy-fuel combustion in the condition relevant to Spark Ignition (SI) engines. First, 1-D (one-dimensional) laminar freely propagating premixed flame is examined to show a consistent combustion temperature for different dilution cases, such that 73% H2O and 66% CO2 dilution ratios are adopted in the following 3-D DNS cases. Four 3-D DNS cases with various turbulence intensities are conducted. It is found that dilution agents can reduce the overall flame temperature but with an enhancement of density weighted flame speed. CO2 dilution case shows the lowest flame speed both in turbulent and laminar cases.
2017-10-08
Technical Paper
2017-01-2193
Andreas Nygren, Anders Karlsson
Abstract When developing new combustion concepts, CFD simulations is a powerful tool. The modeling of spray formation is a challenging but important part when it comes to CFD modelling of non-premixed combustion. There is a large difference in the accuracy and robustness among different spray models and their implementation in different CFD codes. In the work presented in this paper a spray model, designated as VSB2 has been implemented in OpenFOAM. VSB2 differ from traditional spray models by replacing the Lagrangian parcels with stochastic blobs. The stochastic blobs consists of a droplet size distribution rather than equal sized droplets, as is the case with the traditional parcel. The VSB2 model has previously been thoroughly validated for spray formation and combustion of n-heptane. The aim of this study was to validate the VSB2 spray model for ethanol spray formation and combustion as a step in modelling dual-fuel combustion with alcohol and diesel.
2017-10-08
Technical Paper
2017-01-2194
Mateusz Pucilowski, Mehdi Jangi, Sam Shamun, Martin Tuner, Xue-Song Bai
Abstract Heavy-duty direct injection compression ignition (DICI) engine running on methanol is studied at a high compression ratio (CR) of 27. The fuel is injected with a common-rail injector close to the top-dead-center (TDC) with two injection pressures of 800 bar and 1600 bar. Numerical simulations using Reynold Averaged Navier Stokes (RANS), Lagrangian Particle Tracking (LPT), and Well-Stirred-Reactor (WSR) models are employed to investigate local conditions of injection and combustion process to identify the mechanism behind the trend of increasing nitrogen oxides (NOx) emissions at higher injection pressures found in the experiments. It is shown that the numerical simulations successfully replicate the change of ignition delay time and capture variation of NOx emissions.
2017-10-08
Technical Paper
2017-01-2195
Mei Wang, Xianyin Leng, Zhixia He, Shengli Wei, Liang Chen, Yu Jin
Abstract The spark-ignited pre-chamber stratified combustion system is one of the most effective ways of expanding lean-burn ability and improving the performance of a natural gas engine. For these pre-chamber engines, the geometrical structure of orifices between the pre- and main chamber plays a significant role on the gas flow and flame propagation behaviors. The present study aims to investigate the effects of orifice number and diameter on combustion characteristics of a Shengdong T190 natural gas engine through CFD simulation. Various geometrical structures for the pre-chamber orifices were designed, offering variations in the number of orifices (4 to 8), and in the diameter of orifices (1.6mm to 2.9mm). A non-dimensional parameter β was employed to characterize the relative flow area of the orifices in the design. CFD simulations of combustion processes for these designs were carried out using a simplified chemical reaction kinetic mechanism for methane.
Viewing 211 to 240 of 85301