[3liminate]

Hi,

I have two questions and some help would be appreciated!

Q1: I'm modelling a fuselage (without wings) in CFD (in a wind tunnel domain) and was wondering what is the area Star-CCM+ uses when calculating e.g. lift or drag forces?
If I've selected the fuselage region as the input part for force reports, then does is automatically use the frontal area in the calculation, or, the entire body area?

Q2: I've obtained force results for a scaled fuselage model from a 'real life' physical wind tunnel (using a load cell) and wanted to match this in the Star CFD. Consequently, am I correct in assuming the drag results from the physical wind tunnel would be from the frontal area? I'm trying to just validate my physical model results in the Star CFD. Thanks

[fluid23]

1. I think you are confusing force report and force coefficient report. There is no reference area for a force report which, depending on your selections, will integrate pressure and shear distributions across the surfaces you specify as the input. A force coefficient report takes the integrated force and non-dimensionalizes it against reference values, including a user specified area that can be anything you want it to be.

2. I think what you are asking here is; are you correct in assuming that the wind tunnel drag forces were non-dimensionalized using frontal area. This is a question that no one could possibly answer without knowing your reference/source or the specifics of how the data was collected, reduced and presented. I think you are the most qualified person to answer that as you have access to this data.

[3liminate]

Thanks for the reply, I understand now!