I have a question about calculating the pressure drop in a large flow meter across an array of nozzles. Basically its inside of a tunnel... air flows in this tunnel until it reaches a "gate" which is blocked off except for six nozzles of different size, which discharge back into an open tunnel... We know the velocity of the air before the nozzle array (5 m/s), the diameter of the flow meter tunnel (50"), as well as the exit diameter of the six nozzles (6", 3 x 4", 3", and 2"). To be honest, I'm not sure what to do when it comes to the parallel pressure drop through different nozzles. I tried Bernoulli's equation using the total combined exit diameter of the nozzles as my exit point.... It gave me about 1.22 inH2O. But I feel like this calculation is wrong because you can not just add up the nozzle exit diameters when in parallel. Any suggestions?