Thanks everyone and sorry for the late reply! This is what I decided to do after reading replies and I want correction if needed: I calculated the pressure offered by the charcoal height and used it as the static pressure resistance of the system. I had previously determined the quantity of air...
I'm planning on designing a centrifugal fan that will blow air for combustion of charcoal which is contained in a cylindrical drum but I need to know how to estimate the system resistance (the static pressure) and the flow rate.
Please, I'm new to fan design and I don't know how to get my fans...