Learning Forum

[Rizwan]

There are few queries related to rectangular geometry model with edges in y direction both insulated and one edge on x axis maintained at T=0 deg C and the other with some heat flux.There is internal heat generation also.Although the model was developed and solver applied.some help is needed in interpreting the output    

-the mesh has 8 nodes and three elements,How many temp.values will ANSYS solver determine?

-which is /are affected when we input the material characteristic -Governing equations,essential boundary conditions,natural boundary conditions

Regards 

Rizwan

[Rob]

Hi, please can you include details of which solver you're using? Re the effected equations please look in the documentation (click on help inside the solver) and look through: material properties are used within many (most) equations. 

[Rizwan]

I am using Ansys 18.2 and the problem is related to steady state thermal condition.Midsize nodes are not being considered.

[Rob]

So ANSYS Mechanical? 

[Rizwan]

yes and by the way material property will not effect essential boundary condition(T=0),it will definitely affect the governing equation but what about natural boundary condition? 

[peteroznewman]

Rizwan,

I see you want the answer to a quiz question in the edX course.

Why don't you say what you think the answer is and explain why.

We can tell you if you have understood the theory of the mathematics behind the solver.

Regards,
Peter

[Rizwan]

Peter,

You can see I have worked out the problem in terms of ANSYS solution.Its the interpretation part for which I am seeking a guidance.How does one infer from the temp distribution profile the temp.values.Is it 14(no. of colour codes).As far as mathematics is concerned ,the physical problem is converted into mathematical model giving boundary condition and the governing equation,the solver does its part.If we had to do everything in terms of hand calculation why use a software.The fundamentals says that temp values can be determined at the nodes only of the mesh geometry.Two nodes have constant temp(Essen.boundary),temp gradient in y direction is zero.so we expect only 3 values of temp at the three bottom nodes for temp.profiling.

For the second clarification k will not affect the Essen.bound.,but will have an impact on the governing equation,but not sure about normal boundary.

It is with these confusions that I had put this up in the forum.If you feel it is wrong then sorry it seems this is not the place for me.

Regards

Rizwan

 

[peteroznewman]

Rizwan,

A thermal model has 3 elements and 8 nodes. The solver assembles a set of equations in terms of the temperature at these 8 nodes. After has solved the system of equations and determined the values of temperature at these 8 nodes, it uses interpolation to display the temperature anywhere in the domain.

Once you can interpolate, you can color in the elements with 3 colors, 7 colors, 14 colors or more. This is called post-processing.  It occurs after the temperature at just 8 nodes has been computed by the solver.

The quiz question is a bit ambiguous because as you say, two nodes have been assigned a fixed value of temperature, but the system of equations has to include those two nodes in the context of the edX course.  I hope this helps you answer the first question.

Heat flux is a natural boundary condition. What is the equation for Heat Flux?  Does it have a k in it? This should help you answer the question.

Regards,
Peter