Fluid flow equations for a frisbee

[MdAsher]

Hi All,
I'm hoping to work on deriving the governing fluid flow equations for a frisbee in flight theoretically and then to test it on a wind tunnel, and compare results. If u could please help on how do i apply/derive the necessary equations.
Respectful Regards

 

[boneh3ad]

The governing equations are the Navier-Stokes equations. I'm not really sure there are any further simplifications you can make other than introducing a turbulence model instead of trying to solve the equations directly.

 

[bigfooted]

The boundary layer problem of an infinite rotating and translating disc was solved by Rott and Lewellen in 1967:
http://scitation.aip.org/content/aip/journal/pof1/10/9/10.1063/1.1762380

I guess that's as close as you can get to the real thing without doing some serious computing. The problem of the rotating infinite disc (without translation) was solved by von Karman and there is a section on it in the book of Schlichting (probably in most books on boundary layers, it is also in White - Viscous Fluid Flow). This might be a good starting point if you are really looking for a reduced model or analytic solutions and you don't want to solve the Navier Stokes equations.

Some remarks: the flow over the bottom of the frisbee will separate immediately at the edge, so these solutions might still be very far from your measurements. Solving Navier Stokes directly will be too time consuming, and a turbulence model will probably not be able to predict the flow re-attachement on the bottom (and it will still be time consuming, maybe a week on a 16 cores machine for a single simulation using a k-omega model).