Three-dimensional transient numerical simulation for gas exchange process in a four-stroke motorcycle engine

For developing free-piston diesel engine, The two stroke Reverse-Loop scavenging diesel engine E150 was taken as the prototype and a simplified model was built by using CATIA software. Based on the influence of different factors about the gas exchange process，several layouts of scavenging air belt to be built in different schemes. Then the influence of the main structure parameters of scavenging air belt to the gas exchange process were analyzed and a better scheme of structural parameters was obtained.

Download Full-text

Optimization of the Scavenging System Based on Specific Time-Area Value of a Compact Two-Stroke Gasoline Engine

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.538-541.3094 ◽

2012 ◽

Vol 538-541 ◽

pp. 3094-3097

Author(s):

Shou Chen Xing ◽

Chen Hai Guo ◽

Pu Kang Xie ◽

Fei Dong

Keyword(s):

Numerical Simulation ◽

Optimal Design ◽

Gas Exchange ◽

Mathematical Models ◽

Gasoline Engine ◽

Exchange Process ◽

Specific Time ◽

Gas Exchange Process ◽

Stroke Engine

The specific time-area values describe the circulating ability of two-stroke engine ports during the gas exchange process, so they are the main parameters to affect the engine performances [1]. This paper establishes mathematical models of port parameters for symmetrically timing ports of two-stroke gasoline engine with carburetor and crankcase loop scavenging, the emphasis of analysis is specific time-area values of the ports. The mathematical models of specific time-area values which introduced in this paper give the initiative for further research on the numerical simulation and the optimal design of two-stroke engine.

Download Full-text

Experimental research on scavenging process of opposed-piston two-stroke gasoline engine based on tracer gas method

International Journal of Engine Research ◽

10.1177/14680874211036613 ◽

2021 ◽

pp. 146808742110366

Author(s):

Fukang Ma ◽

Wei Yang ◽

Yifang Wang ◽

Junfeng Xu ◽

Yufeng Li

Keyword(s):

Gas Exchange ◽

Exchange Process ◽

Delivery Ratio ◽

Tracer Gas ◽

Piston Motion ◽

Trapped Air ◽

Exchange Performance ◽

Gdi Engine ◽

Gas Exchange Process ◽

Scavenging Efficiency

The scavenging process of two stroke engine includes free exhaust, scavenging, and post intake process, which clears the burned gas in cylinder and suctions the fresh air for next cycle. The gas exchange process of Opposed-Piston Two-Stroke (OP2S) engine with gasoline direct injection (GDI) engine is a uniflow scavenging method between intake port and exhaust port. In order to investigate the characteristics of the gas exchange process in OP2S-GDI engine, a specific tracer gas method (TGM) was developed and the experiments were carried out to analyze the gas exchange performance under different intake and exhaust conditions and opposed-piston movement rule. The results show that gas exchange performance and trapped gas mass are significantly influenced by intake pressure and exhaust pressure. And it has a positive effect on the scavenging efficiency and the trapped air mass. Scavenging efficiency and trapped air mass are almost independent of pressure drop when the delivery ratio exceeds 1.4. Consequently, the delivery ratio ranges from 0.5 to 1.4 is chosen to achieve an optimization of steady running and minimum pump loss. The opposed piston motion phase difference only affects the scavenging timing. Scavenging performance is mainly influenced by scavenging timing and scavenging duration. With the increased phase difference of piston motion, the scavenging efficiency and delivery ratio increased gradually, the trapping efficiency would increase first and decrease then and reaches its maximum at 14°CA.

Download Full-text

Calculation and Design Method Study of the Coil-Wound Heat Exchanger

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1008-1009.850 ◽

2014 ◽

Vol 1008-1009 ◽

pp. 850-860 ◽

Cited By ~ 3

Author(s):

Zhou Wei Zhang ◽

Jia Xing Xue ◽

Ya Hong Wang

Keyword(s):

Heat Transfer ◽

Numerical Simulation ◽

Heat Exchanger ◽

Design Method ◽

Fluid Velocity ◽

Exchange Process ◽

Three Dimensional ◽

Simulation Method ◽

Physical Parameters ◽

Numerical Result

A calculation method for counter-current type coil-wound heat exchanger is presented for heat exchange process. The numerical simulation method is applied to determine the basic physical parameters of wound bundles. By controlling the inlet fluid velocity varying in coil-wound heat exchanger to program and calculate the iterative process. The calculation data is analyzed by comparison of numerical result and the unit three dimensional pipe bundle model was built. Studies show that the introduction of numerical simulation can simplify the pipe winding process and accelerate the calculation and design of overall configuration in coil-wound heat exchanger. This method can be applied to the physical modeling and heat transfer calculation of pipe bundles in coil wound heat exchanger, program to calculate the complex heat transfer changing with velocity and other parameters, and optimize the overall design and calculation of spiral bundles.

Download Full-text

Gas Exchange Process of Four-Stroke Spark Ignition Engines under the Condition of Partial Load at Medium or Low Speed : 4th Report

Bulletin of JSME ◽

10.1299/jsme1958.23.561 ◽

1980 ◽

Vol 23 (178) ◽

pp. 561-566

Author(s):

Hidenori TSAKA ◽

Shin MATSUOKA

Keyword(s):

Gas Exchange ◽

Exchange Process ◽

Spark Ignition ◽

Spark Ignition Engines ◽

Low Speed ◽

Partial Load ◽

Gas Exchange Process

Download Full-text

Numerical Simulation on Cylinder Flow Field of Diesel

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.712-715.1330 ◽

2013 ◽

Vol 712-715 ◽

pp. 1330-1334

Author(s):

Yin Dong Song ◽

Yin Nan Yuan ◽

Chun Ping Wu ◽

Yong Wang Li ◽

Peng Zhe Qi ◽

...

Keyword(s):

Numerical Simulation ◽

Flow Field ◽

Three Dimensional ◽

Swirl Flow ◽

Mixing Rate ◽

Air Mixing ◽

Reduce Emissions ◽

Diesel Cylinder ◽

Cylinder Flow ◽

Transient Numerical Simulation

Three dimensional transient numerical simulation on cylinder flow field of 4B26 diesel was done by AVL FIRE. Detailed flow field structure of diesel cylinder was calculated. The typical swirl flow and squish flow were established in 4B26 diesel engine chamber. swirl flow and squish flow can increase the fuel and air mixing rate, and can improve diesel combustion and can reduce emissions of pollutants. Oil beam could accelerate the air around it.

Download Full-text