CG and CP of the model

I have the moment coefficient that measured by setting the CG as the center. My question is that what should be my CG and CP location input? I heard that it should be the CG location measured from the reference point but I do not know that reference point setting by Simulink?

Answer 1

[Divyajyoti Nayak]

Hi @Ramida,

Simulink does not set any reference point. The center of pressure is the location where the resultant lift and drag forces act, this can be any general moment reference point as long as the rest of the model follows the same reference point. Sp the center of gravity should be measured from the same reference point. Here's some documentation and example links to help:

'Aerodynamic Forces and Moments' Block: https://www.mathworks.com/help/aeroblks/aerodynamicforcesandmoments.html?searchHighlight=moment+coefficient&s_tid=srchtitle_support_results_3_moment+coefficient#mw_15bbc765-f829-4aff-8300-80496e16a474

Example model: https://www.mathworks.com/help/aeroblks/hl-20-with-flight-instrument-blocks-and-visualization-using-unreal-engine.html

In the example model, the 'Aerodynamic Forces and Moments' block is used in 'Forces and Moments' sybsystem inside 'HL20 Airframe' subsystem.