Learning Forum

[m.nikjah]

Dear all,

I have a CFX simulation case of a fan and I want to calculate drag(tangential) and lift(normal) forces on blades. Due to radial placement of blades, it seems that it is not possible to use cartesian coordinate system and force calculation in x, y, z directions will lead to wrong answers.

Blades are shown below:

[rfblumen]

I believe you can calculate lift and drag using an approach outlined in Brennan's text, "Hydrodynamics of Pumps", Chapter 3 (you can access this using this link: https://authors.library.caltech.edu/25019/1/chap3.htm)
You can calculate Fx, Fy over the entire blade or you could break up the blade in sections of a certain span using isoclips in CFD-Post and calculate lift, drag as a function of span. The flow angles can be extracted from CFD-Post after initializing the Turbo Workspace.

[m.nikjah]

Thanks