[msh528]

Hi,

I want to obtain temperature and velocity profiles of flow through four gas turbines, that are placed as depicted below. The simulations are being done for a hoverboard model.

I am just using simple cylinders to depict the turbines. Air enters the turbines through the inlet, the turbine walls provide the heat flux, and the air then exits the exhaust at much higher temperatures.

I am curious about what the turbulence model should be used to model this flow, and if you can in general provide any tips for such a simulation? I'd be grateful.

[msh528]

Images can be accessed on these links:

https://ibb.co/J31Zk0F

https://ibb.co/KNBGNWR

[ghorrocks]

I don't look at third party download sites. Post images directly on this forum.

From what I can see you should consider using a momentum source term to be the turbines. Then you can control the thrust/power they generate without modelling the details inside the turbine. Also the heat flux of the turbines is unlikely to be important, the momentum flux will be the important factor as they gives the thrust.

The choice of turbulence model is unlikely to make much difference. But once you have a working model you can try some models and test this for yourself.

[msh528]

Originally Posted by ghorrocks

From what I can see you should consider using a momentum source term to be the turbines.

Could you please advise where in CFX I can define the turbines as a momentum source terms? Is it the 'specified shear' option under Mass and Momentum in Boundary Details?

[ghorrocks]

Are the turbines are inside the domain? They appear to be. This would mean that the inlet and outlet of the turbines are inside the domain. If this is the case you should use a momentum source term, which can be found when you define a subdomain.

If the turbines have their inlets or outlets outside the domain then you should use an inlet or outlet boundary to define them.