We have to cool a hot cylindrical piece (500 °C) by impinging a cold spray on a specified zone of the side. Which boundary condtions on temperature or heat flux we need to set. Thanks

You should specify the power values in W/m3 as an energy source for the hot piece. If the power value is reducing against time, i.e. you are doing a transient analysis of the cooling, then you will need to write a UDF to define the reduction in terms of the energy vs time.

hope that helps.

By the way, how to make a heat conduction simulation with two solids, for example, two cubics together in Fluent?

How to set up the 2D interface region between these 2 solids?

If you have done spesified the two difference material that connected to each other, FLuent directly apply the new wall between those material, called as " Shadow Shell Wall". If you want to make heat transfer on this, you can simply click this wall and you may spesified the term of heat in this area and the thickness of the shell. But if you want directly simulate the heat transfer without using the Shadow Shell, you have to spesified the temperature of the surface of other material and other material properties like heat conduction and etc. Complete explanation can be found in " How to perform heat transfer using Fluent"

Could you do me a favor in sending me the file.cas and file.dat in Fluent 6? It´s difficult to understand via forum.

I present my geometry with two 3D regions.

http://rapidshare.de/files/41016418/..._2008.rar.html

or

http://www.4shared.com/file/73524138...8_11_2008.html

Do you know if this UDF below is correct?

/************************************************** ************/ /* */ /* User-Defined Function for Unsteady Heat Flux */ /* */ /* Fluent 6 */ /* */ /* Author: Rogerio Brito */ /* Date: November 2008 */ /* */ /* This function prescribes an varying heat flux */ /* at a boundary condition on the cutting tool. */ /* */ /************************************************** ************/

#include "udf.h"

DEFINE_PROFILE(unsteady_heatflux, thread, position) { real heatflux; face_t f; real t = CURRENT_TIME;

heatflux = (14730207.12946*pow((t),3.36869))/(pow((4.82407),3.36869)+pow((t),3.36869));

begin_f_loop(f, thread) {

F_PROFILE(f, thread, position) = heatflux; } end_f_loop(f, thread) }

where pow((t),3.36869) is equal to:

t**3.36869 like in FORTRAN statement.

Thanks,

I don't knw upto what extend you want to simplify your problem

I thought of these as i don't knw the exact problem

a)The spray is of liquid material and the rod does not have internal heat generation. i.e. at sp.temp it is brought to the contact of spray

In this case above you need to model the domain around the rod patch the rod with sp. temp and then model the spray with DPM Model and look the cooling.

Is it enough to give temperatures of the different sides of the cylinder as a boundary conditions or we need to add a source energy term. in this case which fluent command (instruction) can be used.