@oliveroxtoby
Here is a little info about a calculation I have done.
The pic above (cylinder in channel) is a test case. The channel is 6 m long, 2 m high and 100 mm "thick".
Theory:
Diameter cylinder is D=400 mm. Fluid is water with rho=1000 kg/m^3, inlet speed 1,5 m/s.
This gives a pressure of q=1085 N/m^2, Re=5,9*10^5 ==> drag-coeff=0,8 according to DIN4131.
The resulting force on an infinite long cylinder is F=cf*D*q=348 N/m.
openfoam-result, see spreadsheet in paraview pic:
the resulting drag-force on the 10 cm long simulation-cylinder is 35,3 N, so for a 1m part it is 353 N!
I think that is a perfect matching!
(btw: as far as I understood the input-files, openfoam caculates a "normalized" pressure field,
p_openfoam=p_real/density.
So to get the real pressure, you must multiply the calculated field with fluid-density. OK?)
regards Thomas
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