Propeller Airflow Analysis

I have used the momentum blade element theory to anlyze the airflow at the propeller disk. I am warry of the results however - how accurate are the values that can be determined this way for the magnitudes of axial and tangential velocity?

Of greater interest to me is the behaviour of the flow sligtly downstream of the propeller. I would like to be able to determine the magnitudes of the axial and tangential components of the airflow velocity at a specified distance dowstream of the propeller (dependant on radial position as well).

I understand that the axial velocity will double, but is there any rule of thumb or way of estimating where this maximum velocity will occur? More relevant would be a means of determining the contraction of the slipstream diameter at a specified distance. Are there any analyses methods for this, or, again, rules of thumb or empirical data.

Thanks.

 

[Rollerblades]

In Froude theory, for a control volume, you have Q=pi*r^2(V2-V0) where V2 is the speed at radius r.

 

[choy]

I need to design a airplane propeller in the wind tunnel, but I don't know how to choose a correct size. The wing that I am using is 560mm by 300mm (rectangle). what are the factors that leeds to the selection of the propeller?