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Craig Paxton June 10, 2002 12:53

Boundary zones in Gambit for a 3D propeller.
We are wondering if the boundary zones we are going to apply are the correct assumptions.

This experiment is to simulate a propeller flying in an open-air environment. This type of simulation is new to us and we have a few questions.

Geometry: A two blade propeller is attached to a cone that sits atop a cylinder with the same radius (representing a nucelle. This geometry is symmetric and has been cut in half to simply the representation. This geometry is then subtracted from a box to form the flow field. The box is designed so that the inlet, outlet, and outer faces are at least thirty chord lengths from the propeller. Our thought is to have this outlet return to similar conditions as the inlet. Is this enough distance from the propeller, especially in the outlet, with a 60 mph incoming flow and 12000 rpm?

Boundary Conditions: Because we have cut it in half and are planning on using a single rotating reference, using the absolute velocity formulation option, we assume that the cutting plane will be divided into two and assigned as a periodic zone. Correct, any thoughts?

The inlet zone will be applied as a velocity inlet and the outlet as a pressure outlet. The outer faces of the flow volume are initially thought to be a pressure far field.

Are these correct assumptions? If not which boundary conditions are needed?

Another question is "Do we need to create an inlet volume?".

Thanks in advance.


Craig Paxton June 10, 2002 12:57

Re: Boundary zones in Gambit for a 3D propeller.
One other question:

For the propeller blade and nucelle we are going to assign a wall boundary zone. Does the blade need any additional boundary types assigned or will this all be done in Fluent?

Thanks again, Craig

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