NUMERICAL SIMULATION OF TRANSFER AND REACTION PROCESSES IN ETHYLENE PYROLYZER Ⅲ.Numerical Simulation of Combustion and Heat Transfer Processes in Furnaces

Based on the measurements of transient temperature on cylinder head wall in Model 190A diesel engine, the heat transfer processes in cylinder are analysed.

According to heat transfer principles and the process of solving engineering problems by finite element method, examples were given to demonstrate how finite element analysis can be used to describe transient heat transfer through textile fabrics. Details were given to describe how conduction and convection affect temperature distribution and heat loss during heat transfer processes by taking advantage of the quick calculation ability of FEA software MSC.

By simulating the steady heat transfer processes in single-crystal silicon film with thickness of 2~42nm under room temperature (300K), it is found that: 1) in-plane thermal conductivity is about 5~75W/mK, which is below its bulk value at the same temperature,so that the size effect is evident;

A nonlinear two-dimensional thermo-electromagnetic coupling model for the electromagnetic and the heat transfer processes equations is proposed,and a solution approach based on an alternate iteration with a time-step of microwave cycle is suggested.

When the nonuniformities in the imposed temperature differences are increased, large deformations of the liquid-vapor interface occur that lead to an enhancement of the heat transfer processes.

A macroscopic mathematical model for the analysis of the diffusion and heat transfer processes in a bounded periodically micro-stratified thick solid layer will be derived.

A macroscopic model of the diffusion and heat transfer processes in a periodically micro-stratified solid layer

The analysis of the obtained results showed that the flow field is appreciably influenced by the viscosity/temperature parameter, and hence care must be taken to include the variation of viscosity with temperature in the heat transfer processes.

In particular, it is concluded that when the viscosity of a working fluid is sensitive to the variation of temperature, care must be taken to include this effect, otherwise considerable error can result in the heat transfer processes.

In this paper, the fluit cycle and heat transfer process for an axially grooved heat pipe are analysed; and the performance test data for several extruded axially grooved aluminum alloy heat pipes, where ammonia, nitrogen, acetone were used as working fluids are also presented. The test data are compared with the theory prediction. The film coefficients of evaporator and condenser were measured. The empirical formula has been derived for the evaporator film coefficient of heat pipes where...

In this paper, the fluit cycle and heat transfer process for an axially grooved heat pipe are analysed; and the performance test data for several extruded axially grooved aluminum alloy heat pipes, where ammonia, nitrogen, acetone were used as working fluids are also presented. The test data are compared with the theory prediction. The film coefficients of evaporator and condenser were measured. The empirical formula has been derived for the evaporator film coefficient of heat pipes where ammonia is used as working fluid. The heat pipe applications for spacecraft are described. The test performance for circumferentially grooved artery heat pipes and cold gas reservoir variable conductance heat pipe which consist of an axially grooved tube are briefly described. The engineering design method of VCHP was given.

This anticle introduces a more aceurate calculating method for the down-film absorber, a main apparatus in the NH_3 absorp tion refrigerating machine. The absorption of NH_3 is both a mass transfer and a heat transfer process. In the process,the temperature of the absorbing solution is not uniformly decreased by cooling. So it is necessary to divide the tube into many small segments in length, and calculate the absorption and heat transfer rate of the segment one by one, until the...

This anticle introduces a more aceurate calculating method for the down-film absorber, a main apparatus in the NH_3 absorp tion refrigerating machine. The absorption of NH_3 is both a mass transfer and a heat transfer process. In the process,the temperature of the absorbing solution is not uniformly decreased by cooling. So it is necessary to divide the tube into many small segments in length, and calculate the absorption and heat transfer rate of the segment one by one, until the required absorbing degree of the NH_3 has been reached. Thus the number of segments,the lenth of the tube and the area of absorber can be determined. Comparing the area obtained simply by LMT heat transfer method with the area obtained by the aforesaid method, the latter is much smaller than the former. The way to enhance the heat transfer of the tube, in order to shorten the size of the absorber, is also presented in this article.

By managing the heat conduction problem in solids the thermal conductivity is usually taken as a constant, but in reality varying thermal conductivity reveals in every heat transfer process. Therefore, in the present paper, we wish to consider it to vary with the space coordinate according to a linear and an exponential law; basing on this proposal we have been able to set up six second order heat conduction differential equations. By the way, for the case of variable density, specific heat...

By managing the heat conduction problem in solids the thermal conductivity is usually taken as a constant, but in reality varying thermal conductivity reveals in every heat transfer process. Therefore, in the present paper, we wish to consider it to vary with the space coordinate according to a linear and an exponential law; basing on this proposal we have been able to set up six second order heat conduction differential equations. By the way, for the case of variable density, specific heat as well as thermal conductivity, we have been successful to deduce other similar six heat transfer differential equations.