Analysis and Modeling of Heat Transfer in the SI Engine Exhaust System During Warm-Up

2007 ◽  
Author(s):  
Stefan Heller ◽  
Georg Wachtmeister
Keyword(s):  
Heat Transfer ◽  
Exhaust System ◽  
Si Engine ◽  
Engine Exhaust ◽  
Warm Up

Engine exhaust system design based on heat transfer computation

1999 ◽  
Vol 40 (10) ◽  
pp. 1057-1072 ◽  
Author(s):  
I.P. Kandylas ◽  
A.M. Stamatelos
Keyword(s):  
Heat Transfer ◽  
System Design ◽  
Exhaust System ◽  
Engine Exhaust

scholarly journals Heat transfer in exhaust system of a cold start engine at low environmental temperature

2010 ◽  
Vol 14 (suppl.) ◽  
pp. 209-220 ◽  
Author(s):  
Snezana Petkovic ◽  
Radivoje Pesic ◽  
Jovanka Lukic
Keyword(s):  
Heat Transfer ◽  
Environmental Temperature ◽  
Exhaust System ◽  
Cold Start ◽  
Design Parameters ◽  
Engine Exhaust ◽  
Engine Emission ◽  
Environmental Temperatures ◽  
Stationary Heat Transfer ◽  
Off Time

During the engine cold start, there is a significantly increased emission of harmful engine exhaust gases, particularly at very low environmental temperatures. Therefore, reducing of emission during that period is of great importance for the reduction of entire engine emission. This study was conducted to test the activating speed of the catalyst at low environmental temperatures. The research was conducted by use of mathematical model and developed computer programme for calculation of non-stationary heat transfer in engine exhaust system. During the research, some of constructional parameters of exhaust system were adopted and optimized at environmental temperature of 22?C. The combination of design parameters giving best results at low environmental temperatures was observed. The results showed that the temperature in the environment did not have any significant influence on pre-catalyst light-off time.

The Design and Rating of the Pressure Exchange Steam Ejector for a Waste Heat Driven Automotive Air Conditioning System

2009 ◽  
Author(s):  
David M. Gould ◽  
Charles A. Garris
Keyword(s):  
Heat Transfer ◽  
Air Conditioning ◽  
Waste Heat ◽  
Exhaust System ◽  
Minimum Condition ◽  
Engine Exhaust ◽  
Air Conditioning System ◽  
Automotive Air Conditioning ◽  
Exhaust Heat ◽  
Pressure Exchange

A pressure exchange ejector invented by George Washington University’s Professor Charles Garris has been considered a novel concept for energy conversion and utilization of two working fluids. One of the applications of the pressure exchange ejector involves taking the captured waste heat from the car’s engine to assist in running its air conditioning system. This study involves implementing the pressure exchange ejector in a modified vapor compression air conditioning system and determining its feasibility with performance and sizing for a typical midsize sedan. The specific midsize sedan chosen in the analysis is the inline six-cylinder BMW 530i sedan. The analysis involves comparing previous results and data of high and low cooling loads from the conventional automotive air conditioning (A/C) system using R-134a refrigerant with a new steam pressure exchange ejector A/C system. The pressure exchange (PE) ejector similar to the conventional ejector can be represented by the turbomachinery analog. Desirable theoretically efficiencies of the PE ejector using the turbomachinery analog are varied to determine the minimal efficiency required to run the ejector air conditioning system. The performances of the ideal and minimum condition for the PE ejector A/C system are determined to view the potential and feasibility of the system. The system consists of environmentally friendly steam as a refrigerant and replaces the conventional A/C system’s engine driven compressor with an ejector and a second loop for waste heat recovery from the car’s engine exhaust system. Simulation tests of varying ejector efficiency under the designed A/C system and vehicle conditions are conducted through computational heat transfer and thermodynamic analysis using MATLAB/Simulink. The software is a numerical calculation and visualization software program where various environmental, thermodynamic, heat transfer, and sizing conditions can be monitored. Engine exhaust heat and conventional air conditioning results and properties are obtained through previous experiments and analysis at respected universities and laboratories.

scholarly journals Experimental Determination of Stator Endwall Heat Transfer

1989 ◽  
Author(s):  
Robert J. Boyle ◽  
Louis M. Russell
Keyword(s):  
Heat Transfer ◽  
Liquid Crystal ◽  
Test Section ◽  
Electrical Power ◽  
Exhaust System ◽  
Ambient Air ◽  
Reynolds Numbers ◽  
Inlet Velocity ◽  
Turbine Vane

Local Stanton numbers were experimentally determined for the endwall surface of a turbine vane passage. A six vane linear cascade having vanes with an axial chord of 13.81 cm was used. Results were obtained for Reynolds numbers based on inlet velocity and axial chord between 73,000 and 495,000. The test section was connected to a low pressure exhaust system. Ambient air was drawn into the test section, inlet velocity was controlled up to a maximum of 59.4 m/sec. The effect of the inlet boundary layer thickness on the endwall heat transfer was determined for a range of test section flow rates. The liquid crystal measurement technique was used to measure heat transfer. Endwall heat transfer was determined by applying electrical power to a foil heater attached to the cascade endwall. The temperature at which the liquid crystal exhibited a specific color was known from a calibration test. Lines showing this specific color were isotherms, and because of uniform heat generation they were also lines of nearly constant heat transfer. Endwall static pressures were measured, along with surveys of total pressure and flow angles at the inlet and exit of the cascade.

scholarly journals Predicting unsteady heat transfer effect of vehicle thermal management system using steady velocity equivalent method

2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110259
Author(s):  
Xiao Guoquan ◽  
Wang Huaming ◽  
Chen Lin ◽  
Hong Xiaobin
Keyword(s):  
Heat Transfer ◽  
Thermal Management ◽  
Management System ◽  
Exhaust System ◽  
Transfer Effect ◽  
Unsteady Heat Transfer ◽  
Thermal Management System ◽  
Comparison Results ◽  
Equivalent Method ◽  
Steady Velocity

In the process of vehicle development, the unsteady simulation of thermal management system is very important. A 3D-CFD calculation model of vehicle thermal management is established, and simulations were undertaken for uphill with full loads operations condition. The steady results show that the surface heat transfer coefficient increases to the quadratic parabolic relationship. The unsteady results show that the pulsating temperatures of exhaust and external airflow are higher than about 50°C and lower than 10°C, respectively, and the heat dissipating capacities are higher than about 11%. Accordingly, the conversion equivalent exhaust velocity increased by 1.67%, and the temperature distribution trend is basically the same as unsteady results. The comparison results show that the difference in the under-hood should be not noted, and that the predicted exhaust system surface temperatures using steady velocity equivalent method are low less 10°C than the unsteady results. These results show the steady velocity equivalent method can be used to predict the unsteady heat transfer effect of vehicle thermal management system, and the results obtained by this method are basically consistent with the unsteady results. It will greatly save computing resources and shorten the cycle in the early development of the vehicle thermal management system.

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