Learning Forum

[Deus Ex Machina]

Hi all,

I'm trying know how walls of impeller can influence 'turbo-variables' like pressure ratio, etc.

I have made the whole machine: diffuser, impeller. CFX and turbogrid. Not Fluent.

The boundary condition over walls is Heat transfer: temperature. This temperature is fixed for each simulation.

But I dont really know how I should estimate the heat. I thought with CFD-post function: intArea(Wall Heat Flux)@impeller walls but it gives me a little strange thermal power.

The boundary conditions on the impeller walls are:

[rfblumen]

I would first run the case with adiabatic walls. You could then apply a temperature to the walls to assess the effect on performance (i.e. pressure ratio, efficiency) and compare with the adiabatic case. You could also run a range of different wall temperatures to further determine the influence of wall temperature on performance. nTo determine if the applied wall temperature is meaningful you may need to expand the model to include the component generating the heat and run the case as a Conjugate Heat Transfer model. See CFX Tutorial 16 for an example.nn

[Deus Ex Machina]

I would first run the case with adiabatic walls. You could then apply a temperature to the walls to assess the effect on performance (i.e. pressure ratio, efficiency) and compare with the adiabatic case. You could also run a range of different wall temperatures to further determine the influence of wall temperature on performance. To determine if the applied wall temperature is meaningful you may need to expand the model to include the component generating the heat and run the case as a Conjugate Heat Transfer model. See CFX Tutorial 16 for an example.https://forum.ansys.com/discussion/comment/106021#Comment_106021

Thank you very much for your answer, I really appreciate it.nI am already doing the first cases varying the temperature of the walls and checking the pressure / temperature relationship, etc.nI am using Wall Heat Flux (integrate into walls, thermal power W) to take into account the importance of heat, do you think this is a good idea?nwhat other variables should I check for this purpose (I have already checked: torque, wall heat flux and pressure contours, etc.)nI don't understand the purpose of Conjugate Heat Transfer Model, I thought it was to study the structural interaction with fluids, could you explain this a bit?nI thank you again for your advice and help.n