At first, I will try to describe my problem.
I have a compressed air at 0.4 MPa (4 bars) that goes trough a control valve and a flow meter into two 5 mm pipes.
Flow meter shows the value of 200 normalized liters/min (100 l/min into each pipe). According to a simple equation Q=Area*velocity this should mean that the velocity of the air coming from the pipe should be around 82 m/s (maybe I am incorrect and it doesn't work like this).
My problem is that the speed is nowhere near this value. I didn't measure it with a proper tool but I know what It should feel like to have outlet speed around 80 m/s. I guess the speed is no more than 20 m/s (the air speed is similar to the speed of air you are able to blow from your mouth with pursed lips).
My cfd simulation also showed the speed around 80-90 m/s with inlet flow of 100 l/min. So where can be the problem? I tested two different flowmeters, both with similar results. Is my calculation wrong or is there something wrong with the flowmeters? Flowmeter were just ordinary cheaper ones.