Learning Forum

[Muhammad Imaduddin Hanif]

Hello, I conducted a simulation using Ansys HAWT Fluent with meshing and found that the coefficient of pressure values for TSR 5-8 should have decreased significantly, but this trend did not align with the BEM method. The graph, with the blue line representing the results from Ansys Fluent with meshing and the orange line representing the results from the BEM method, illustrates this discrepancy. The Cp results for TSR 1-4 are in agreement, but not for TSR 5-8. Do you have any suggestions or recommendations?

[C N]

Hello Hanif,

The Blade element momentum method for Hawt analysis at High tip speed ratios is not very accurate due to the assumption of Ignoring the the static pressure drop caused by wake rotation such that the pressure in far upstream of the rotor equals that in far downstream.It Underpredicts the aerodynamic forces at the root . I suggest you to validate the results with the improved BEM theory with Glauert's tip and shen's tip correction. Can you please provide more information on the boundary conditions, solution methods which you used for the Hawt simulation settings and what approach you have used the Moving refernece frame or the sliding mesh technique.

I recommend you to use the Blade row interaction method for accurate modelling in Ansys fluent.  

I am attaching the user guide link for best practices and its limitations on creating the interfaces using the turbo workflow .

The interface is implicitly defined as a Frozen Rotor or a Transient Rotor-Stator based on the Fluid zone motion specification.

Usually the Transient Rotor-stator approach is accurate.

13.3. Blade Row Interaction Modeling (ansys.com)

I hope this helps you in your simulation and helps you in understanding the result behaviour of the BEM method with the fluent results.

Thanks,

Chaitanya natraj