Radial and tangential velocity

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1

Hi to everyone,

Very silly question here. But i have not found a proper answer yet. Given the velocity profile in the coordinate direction (U_X, U_Z) over a plane XZ plane, with Y normal, (i.e in my case a slice of an annular duct) i have to compute the radial and tangential velocity. Is so right the following procedure?

  1. Compute the angle alfa with the phyton calculator as suggested here [quote=“Kyoshimi, post:2, topic:12796, username:Kenichiro-Yoshimi”]
    arctan2(points[:,2], points[:,0])
    [/quote]. In my case i put [:,2] since the coordinate is along the Z direction;

  2. Estimate the following scalars simply using the calculator U_rad=U_X*cos(a)+U_Z*sin(a); and U_tan=U_Z*cos(alfa)-U_X*sin(alfa);. Where U_X and U_Z are scalars too.

Have i to add something else (e.g the coordinate results as option)? Or must i consider the vectorial product (e,g including IHat and kHat)?

I know it’s a trivial question but i want to be sure of this.

alfa
alfa899×486 18.8 KB

UX
UX899×486 37.3 KB

UZ
UZ899×486 40.5 KB

2

Check this thread: Polar Velocity components - #2 by FEngineer

And please also upvote the feature request mentioned there if you’d like to be able to do it with built-in tools.