Improvement of Transient Heat Transfer Models for the Coupled 3-D Moving Piston Assembly-Liner System

2007 ◽  
Author(s):  
Yankun Jiang ◽  
Zhien Liu ◽  
Rolf D. Reitz ◽  
Zheling Dong ◽  
Xiaoming Ye
Keyword(s):  
Heat Transfer ◽  
Gasoline Engine ◽  
Sparse Matrix ◽  
Cylinder Liner ◽  
Heat Transfer Model ◽  
Transient Heat Transfer ◽  
Transfer Model ◽  
Piston Rings ◽  
Liner System ◽  
Piston Assembly

A transient heat transfer model for the coupling 3-D moving piston assembly-liner system has been successfully improved for predicting temperature distributions in the components of internal combustion engine chamber. In the model the effect of the 3-D friction heat generated at the piston ring/cylinder liner interfaces and the multi-dimensional lubricant film thickness between the piston rings and the liner has been taken into account. A directly coupled finite element method (FEM) is employed in the model for establishing the heat transfer relation among the moving piston assembly-cylinder liner components. A 3-D discrete model of the coupling system is formulated, which includes the piston rings, piston, liner and cylinder. Due to the complexity of the temperature stiffness matrix, a sparse matrix data structure is employed in the model to save the memory and calculation time. Finally, the 3-D coupling heat transfer model has been used to analyze heat transfer processes in a gasoline engine.

Transient Heat Transfer Simulation of the Coupling 3-D Moving Piston Assembly-Lubricant Film-Liner System

2006 ◽  
Author(s):  
Liu Zhien ◽  
Jiang Yankun ◽  
Chen Guohua ◽  
Yang Wanli
Keyword(s):  
Heat Transfer ◽  
Piston Ring ◽  
Cylinder Liner ◽  
Heat Transfer Model ◽  
Lubricant Film ◽  
Transient Heat Transfer ◽  
Transfer Model ◽  
Friction Heat ◽  
Liner System ◽  
Piston Assembly

Transient heat transfer model of the coupling 3-D moving piston assembly-lubricant film-liner system is successfully developed for predicting the temperature distributions in the component system of internal combustion chamber, in which the effect of the friction heat generated at the piston ring/cylinder liner interfaces has been taken into account. The finite element method (FEM) is employed in the model for establishing the heat transfer relation among the moving piston assembly-lubricant film-cylinder liner. The 3-D discrete model of the coupling system is obtained by hypothesizing the lubricant film as 1-D thermal resistances and the friction heat as heat flux boundary conditions. The allocation and distribution model of friction heat on piston ring pack and liner are also established. The 3-D coupling heat transfer model has been used to analyze the heat transfer of a gasoline engine.

Development of transient heat transfer model for controlled gradient drilling

2019 ◽  
Vol 148 ◽  
pp. 331-339 ◽  
Author(s):  
Hongwei Yang ◽  
Jun Li ◽  
Gonghui Liu ◽  
Jiangshuai Wang ◽  
Kuidong Luo ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Model ◽  
Transient Heat Transfer ◽  
Transfer Model

Transient Heat Transfer of Piston/Rings/Liner System in Diesel Engines

2005 ◽  
Author(s):  
Daxi Xiong ◽  
Tian Tian ◽  
Victor Wong
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Transfer Process ◽  
Diesel Engines ◽  
Frictional Heating ◽  
Heat Transfer Process ◽  
Transient Heat Transfer ◽  
Transient Temperature ◽  
Piston Rings ◽  
Liner System

In diesel engines, transient heat transfer in the piston/rings/liner system greatly affects the performance of the engine, such as in carbon deposit buildup, microwelding, lubricant degradation, and changing mechanical properties of the materials. The current work aims at studying the local piston/rings/liner transient heat-transfer process by incorporating real time dynamics of the rings in sufficient detail. In the present study, several techniques have been adopted to simulate the transient heat transfer process, with fully-incorporated ring dynamics. These techniques include using the model/submodel approach, local refined mesh approach, and the virtual thermal conductivity approach. The transient temperature and heat flux profiles in the piston and rings are illustrated. The results show that the relative movement of the rings greatly affects the temperature/heat flux distribution and the peak temperature in the top ring. The friction heating between the top ring and the liner is also evaluated. The analysis demonstrates that under some extreme conditions when frictional heating reaches its peak value, some heat flux directs back to enter the ring.

Isentropic Compressor Efficiency Calculation Method for Small Gasoline Engine Turbocharger Using Supplier Performance Maps

2021 ◽  
Author(s):  
Georges Salameh ◽  
Guillaume Goumy ◽  
Pascal Chesse
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Gasoline Engine ◽  
Experimental Tests ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Flow Equations ◽  
Adiabatic Flow ◽  
Efficiency Calculation ◽  
Isentropic Efficiency

Abstract A turbocharger efficiency performance map given by the supplier is calculated using adiabatic flow equations and non-adiabatic experimental data. The experimental data used for this calculation is measured in hot gas stand conditions which are not adiabatic and the efficiency calculation needs correction. This paper presents a method to correct the isentropic efficiency of a compressor using the supplier maps and a heat transfer model applied on the compressor. Water is circulating in the central housing to cool the turbocharger and this water flow could be considered as insulation for heat transfer between the compressor and the turbine. The thermal effect of the turbine on the compressor is then neglected and the compressor heat flux is calculated and used to correct the isentropic efficiency calculation. The heat transfer is considered between the compressor and the surrounding environment and between the compressor and the central housing. Experimental adiabatic measurements are used to validate the model. Experimental tests are carried with different oil and water temperatures combinations to test the accuracy of the heat transfer model with these different combinations.

Three Dimensional Transient Heat Transfer Model for Steel Billet Heating in Reheat Furnace

2012 ◽  
Author(s):  
Satish Kumar Dubey ◽  
Neelesh Agarwal ◽  
P. Srinivasan
Keyword(s):  
Heat Transfer ◽  
Temperature Field ◽  
Oxide Scale ◽  
Three Dimensional ◽  
Heat Transfer Model ◽  
Heat Diffusion ◽  
Transient Heat Transfer ◽  
Transfer Model ◽  
Scale Thickness ◽  
Reheating Process

In steel rolling mills reheat furnaces are used to heat the billets prior to rolling processes. Reheating is one of the most energy intensive processes in the steel industries. Inadequate temperature measuring techniques and extremely complex analytical solution for temperature filed calculations demands suitable numerical model. In the present work a three dimensional transient heat transfer model is developed for billet heating in reheat furnaces. Conduction heat transfer within the billets is modeled using Finite Difference Method (FDM). Fully implicit spatial discretization approximation was used for three dimensional heat diffusion equation of billet. The three dimensional model takes into account the temperature dependent thermo physical properties, reaction heat effect and growing oxide layer. Algorithm is implemented in MATLAB® to solve three dimensional discretization equations. Model is capable of predicting the temperature field for billet and oxide scale thickness for any residence time. The predicted results are in reasonable concurrence with available data. The main objective of this work is to predict billet temperature field and oxide scale thickness for the various residence times, which may be vital for development of energy efficient optimization strategy for reheating process.

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