Ross probably knows this right off the bat...
Given the typical aircraft header style oil cooler (Stewart - Warner, Airflow Products, etc) of a theoretical aperture area i.e 6x7 = 42 inches, how much area is lost to purely mechanical intrusion? Some of it is easy to calculate, like the multiplying the area of the cross tubes by their number, but what about the fin matrix itself? Quick math says the nominal area is reduced by about 30% by the "big", easy to count stuff. Is there a rule of thumb that takes the rest into account? Can you say "40% of nominal area is lost to blockage in a typical Hx..."?
Im trying to feed a new, bigger oil cooler with a short duct off the baffles, and I dont have a lot of real estate - just trying to see how small of a hole I can go before I start choke the cooler.
Given the typical aircraft header style oil cooler (Stewart - Warner, Airflow Products, etc) of a theoretical aperture area i.e 6x7 = 42 inches, how much area is lost to purely mechanical intrusion? Some of it is easy to calculate, like the multiplying the area of the cross tubes by their number, but what about the fin matrix itself? Quick math says the nominal area is reduced by about 30% by the "big", easy to count stuff. Is there a rule of thumb that takes the rest into account? Can you say "40% of nominal area is lost to blockage in a typical Hx..."?
Im trying to feed a new, bigger oil cooler with a short duct off the baffles, and I dont have a lot of real estate - just trying to see how small of a hole I can go before I start choke the cooler.