Hi, In the homogeneous case, the results of the filter are the forces averaged along the homogeneous direction, i.e. F/Lz. Except for considering Lz, the force is in dimensional form. Therefore, the drag coefficient is Cd = 2*Fd / (rho*U*U*D) where D is the characteristic length in the xy plane. Cheers, Douglas Em qua, 12 de dez de 2018 às 16:56, Moto Light <redamansyhh@gmail.com> escreveu:
Hi All,
My case is incompressible flow case and I am using two different velocity inlets, like: --------------------------------------------------- <REGION REF="0"> <!-- Inlet_upper --> <D VAR="u" VALUE="3" /> <D VAR="v" VALUE="0" /> <N VAR="p" USERDEFINEDTYPE="H" VALUE="0"/> </REGION>
<REGION REF="1"> <!-- Inlet_lower --> <D VAR="u" VALUE="1" /> <D VAR="v" VALUE="0" /> <N VAR="p" USERDEFINEDTYPE="H" VALUE="0"/> </REGION> ----------------------------------------------------- Re = value Kinvis = 1./Re My characteristic length D =1
and i have a problem in the Cd calculation even in Fd drag force value, I need to know when I am using Aerodynamics filter to calculate the forces around my body, which value i have from this filter???
this filter produce forces file, when i plot 1:4 columns ((4 is the total force in X direction)), is it the force directly (( the user guide says it calculate the pressure and viscous contributions are computed in each direction ))
which means it is the Fd Cd = 2*Fd / (rho*U*U*A)
(( Note: for the Base cases as a Validation case using one inlet velocity value and with using velocity equal 1, I just take this forces results and multiplied by 2 it gives the write value like considering rho =1 U=1 A=1))
I am using homogeneous expansion for my mesh in the spanwise direction, also when I tried to use two different spanwise lengths, the forces output was the same How???? is Aerodynamics filter give us Fd/A ?
Thanks,
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