Design optimization of exhaust manifold’s bending radius for spark ignition (SI) engine through CFD analysis on low end RPM using Taguchi’s method

2021 ◽  
Author(s):  
R. Murali ◽  
A. B. Shahriman ◽  
Z. M. Razlan ◽  
N. S. Kamarrudin ◽  
I. Azizul Aziz ◽  
...  
Keyword(s):  
Design Optimization ◽  
Spark Ignition ◽  
Cfd Analysis ◽  
Taguchi’S Method ◽  
Si Engine ◽  
Bending Radius

Aerodynamic Automobile Shape Optimization by Incorporating Reverse Shape Design Method With CFD Analysis

2017 ◽  
Author(s):  
Kisun Song ◽  
Kyung Hak Choo ◽  
Jung-Hyun Kim ◽  
Dimitri N. Mavris
Keyword(s):  
Design Optimization ◽  
Aerodynamic Drag ◽  
Design Method ◽  
Shape Design ◽  
Cfd Analysis ◽  
Simple Arithmetic ◽  
Design Variables ◽  
3D Geometry ◽  
Geometric Entity ◽  
Aerodynamic Drag Reduction

In modern automotive industry market, there have been a lot of state-of-art methodologies to perform a conceptual design of a car; functional methods and 3D scanning technology are widely used. Naturally, the issues frequently boiled down to a trade-off decision making problem between quality and cost. Besides, to incorporate the design method with advanced optimization methodologies such as design-of-experiments (DOE), surrogate modeling, how efficiently a method can morph or recreate a vehicle’s shape is crucial. This paper accomplishes an aerodynamic design optimization of rear shape of a sedan by incorporating a reverse shape design method (RSDM) with the aforementioned methodologies based on CFD analysis for aerodynamic drag reduction. RSDM reversely recovers a 3D geometry of a car from several 2D schematics. The backbone boundary lines of 2D schematic are identified and regressed by appropriate interpolation function and a 3D shape is yielded by a series of simple arithmetic calculations without losing the detail geometric features. Besides, RSDM can parametrize every geometric entity to efficiently manipulate the shape for application to design optimization studies. As the baseline, an Audi A6 is modeled by RSDM and explored through CFD analysis for model validation. Choosing six design variables around the rear shape, 77 design points are created to build neural networks. Finally, a significant amount of CD reduction is obtained and corresponding configuration is validated via CFD.

scholarly journals Phenomenological model for determining velocity field of LPG jet in combustion chamber of direct injection S.I. engine

2004 ◽  
Vol 26 (2) ◽  
pp. 83-92
Author(s):  
Bui Van Ga ◽  
Phung Xuan Tho ◽  
Nhan Hong Quang ◽  
Nguyen Huu Huong
Keyword(s):  
Combustion Chamber ◽  
Phenomenological Model ◽  
Direct Injection ◽  
Spark Ignition ◽  
Velocity Profiles ◽  
Gas Jet ◽  
Liquefied Petroleum Gas ◽  
Si Engine ◽  
Si Engines ◽  
Stratified Combustion

A phenomenological model has been established to predict the velocity distribution of LPG (Liquefied Petroleum Gas) jet in combustion chamber of spark ignition (SI) engine. A shaped coefficient \(\beta\) governing the similarity of velocity profiles of LPG jets has been defined based on the theoretical and experimental analyses of turbulent diffusion jets. The results show that \(\beta\) is constant for steady jet but it is not the case for unsteady one. The model will enable us to calculate the velocity profiles of LPG jet after ending injection. This is necessary for research of stratified combustion in direct injection LPG SI engines.

Experiments and Modeling of Flame/Wall Interaction in Spark-Ignition (SI) Engine Conditions

2013 ◽  
Author(s):  
Olivier Laget ◽  
Laëtitia Muller ◽  
Karine Truffin ◽  
Julian Kashdan ◽  
Rajesh Kumar ◽  
...  
Keyword(s):  
Spark Ignition ◽  
Si Engine ◽  
Wall Interaction

scholarly journals Study on the Effect of Second Injection Timing on the Engine Performances of a Gasoline/Hydrogen SI Engine with Split Hydrogen Direct Injecting

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5223
Author(s):  
Guanting Li ◽  
Xiumin Yu ◽  
Ping Sun ◽  
Decheng Li
Keyword(s):  
Numerical Study ◽  
Direct Injection ◽  
Mixture Distribution ◽  
Spark Ignition ◽  
Injection Timing ◽  
Si Engine ◽  
Excess Air ◽  
Crank Angle ◽  
Hc Emissions ◽  
Main Factor

Split hydrogen direct injection (SHDI) has been proved capable of better efficiency and fewer emissions. Therefore, to investigate SHDI deeply, a numerical study on the effect of second injection timing was presented at a gasoline/hydrogen spark ignition (SI) engine with SHDI. With an excess air ratio of 1.5, five different second injection timings achieved five kinds of hydrogen mixture distribution (HMD), which was the main factor affecting the engine performances. With SHDI, since the HMD is manageable, the engine can achieve better efficiency and fewer emissions. When the second injection timing was 105° crank angle (CA) before top dead center (BTDC), the Pmax was the highest and the position of the Pmax was the earliest. Compared with the single hydrogen direct injection (HDI), the NOX, CO and HC emissions with SHDI were reduced by 20%, 40% and 72% respectively.

Design optimization of duct-type AUVs using CFD analysis

2015 ◽  
Vol 8 (4) ◽  
pp. 233-245 ◽  
Author(s):  
Dong-Joon Won ◽  
Joonwon Kim ◽  
Jinhyun Kim
Keyword(s):  
Design Optimization ◽  
Cfd Analysis

Study of low load performance on a two-stroke direct injection spark ignition aero-piston engine fuelled with diesel

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Rui Liu ◽  
Haocheng Ji ◽  
Minxiang Wei
Keyword(s):  
Fuel Consumption ◽  
Direct Injection ◽  
Spark Ignition ◽  
Injection Timing ◽  
Ignition Energy ◽  
Power Performance ◽  
Si Engine ◽  
Content Type ◽  
Low Load ◽  
Load Conditions

Purpose The purpose of this paper is to investigate power performance, economy and hydrocarbons (HC)/carbon monoxide (CO) emissions of diesel fuel on a two-stoke direct injection (DI) spark ignition (SI) engine. Design/methodology/approach Experimental study was carried out on a two-stroke SI diesel-fuelled engine with air-assisted direct injection, whose power performance and HC/CO emissions characteristics under low-load conditions were analysed according to the effects of ignition energy, ignition advance angle (IAA), injection timing angle and excess-air-ratio. Findings The results indicate that, for the throttle position of 10%, a large IAA with adequate ignition energy effectively increases the power and decrease the HC emission. The optimal injection timing angle for power and fuel consumption is 60° crank angle (CA) before top dead centre (BTDC). Lean mixture improves the power performance with the HC/CO emissions greatly reduced. At the throttle position of 20%, the optimal IAA is 30°CA BTDC. The adequate ignition energy slightly improves the power output and greatly decreases HC/CO emissions. Advancing the injection timing improves the power and fuel consumption but should not exceed the exhaust port closing timing in case of scavenging losses. Burning stoichiometric mixture achieves maximum power, whereas burning lean mixture obviously reduces the fuel consumption and the HC/CO emissions. Practical implications Gasoline has a low flash point, a high-saturated vapour pressure and relatively high volatility, and it is a potential hazard near a naked flame at room temperature, which can create significant security risks for its storage, transport and use. The authors adopt a low volatility diesel fuel for all vehicles and equipment to minimise the number of different devices using various fuels and improve the potential military application safety. Originality/value Under low-load conditions, the two stroke port-injected SI engine performance of burning heavy fuels including diesel or kerosene was shown to be worse than those of gasoline. The authors have tried to use the DI method to improve the performance of the diesel-fuelled engine in starting and low-load conditions.

The Lean Mixture Operational Limits of a Spark Ignition Engine When Operated on Fuel Mixtures

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Hailin Li ◽  
Ghazi A. Karim ◽  
A. Sohrabi
Keyword(s):  
Engine Performance ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Si Engine ◽  
Lean Mixture ◽  
Si Engines ◽  
Unstable Combustion ◽  
Fuel Mixtures ◽  
Traditional Approaches ◽  
Combustion Processes

The operation of spark ignition (SI) engines on lean mixtures is attractive, in principle, since it can provide improved fuel economy, reduced tendency to knock, and extremely low NOx emissions. However, the associated flame propagation rates become degraded significantly and drop sharply as the operating mixture is made increasingly leaner. Consequently, there exist distinct operational lean mixture limits beyond which satisfactory engine performance cannot be maintained due to the resulting prolonged and unstable combustion processes. This paper presents experimental data obtained in a single cylinder, variable compression ratio, SI engine when operated in turn on methane, hydrogen, carbon monoxide, gasoline, iso-octane, and some of their binary mixtures. A quantitative approach for determining the operational limits of SI engines is proposed. The lean limits thus derived are compared and validated against the corresponding experimental results obtained using more traditional approaches. On this basis, the dependence of the values of the lean mixture operational limits on the composition of the fuel mixtures is investigated and discussed. The operational limit for throttled operation with methane as the fuel is also established.

The Influences of Spark Ignition on Combustion Properties at Lean Condition in SI Engine

2018 ◽  
Vol 2018.71 (0) ◽  
pp. E12
Author(s):  
Atsushi YAGI ◽  
Ko SHIMIZU ◽  
Mitsuhiro IKEDA ◽  
Yukihide NAGANO ◽  
Toshiaki KITAGAWA
Keyword(s):  
Spark Ignition ◽  
Si Engine ◽  
Combustion Properties
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