Issue regarding Drag Coefficient
 

Hello, I am doing CFD for the first time, so my doubt might be trivial.

I am doing an external flow calculation over an Airship, keeping the domain as Pressure Far-Field. I have named parts in my geometry, named as Gondola, Hull and Fin (just mentioning in case it helps). I select these parts in the solution monitor and enable the plotting of cd values.

My requirement, I want to vary the angles of the gondola front and back, and get an optimum minimum drag and flow separation situation.

Doubt 1. Since I need the forces in x direction, I print the forces after calculations are done and I get total forces, pressure and viscous on each part along with their respective Coefficients and check the x part.
In the few different iterations I have done, the gondola viscous coefficient comes out between 5-10 and the total cd that is output in my folder as a result of my solution monitor initialisation comes between 1900-2100.

I find both these values unreasonable, are these really drag coefficients? Am I doing something wrong?

Doubt 2 Is it okay if I just check the cd value, or do I need to see flow separation too. I personally don't think it is necessary because cd values are a result of flow separation. So higher separation should naturally result in higher cd values.

Please hepl me know how to proceed in the correct direction. :confused: