BYU Idaho ME 465 Pneumatic Flow Rate Calculations

[@eidalfalasi3555]

This the most simpliest easiest illustration i have ever listened thanks u made my day sir!!!

[@keithhuckabee9859]

Excellent video

[@sebastianb-v2887]

At 4:21 you mention the "textbook". What textbook would that be? Great video and explanation. Thank you :)

[@Themrjakecollins]

What would be the formula for working out the pressure and flow rate at the neck for a given diameter at P1 and given speed of flow? I want to work out how much I can increase a pressure and volume of air in a narrowed pipe where the larger diameter acts as a scoop to for more air. Thank thanks for any help.

[@dhxl]

I don't get where Q = 22.5 * Cv * sqrt ((p1-p2)*p2/T1) comes from. what is capacity coeff? Why it is = 3 here? For the Venturi effect flow rate can be calculated as a function of areas, pressures and density.

[@aaronschellenberg]

Gases can travel over the speed of sound, they just can't do so within the neck. If you want a gas to go faster than the speed of sound then you have to bell out the nozzle after the neck to allow it to continue to accelerate. This is why rocket nozzles will bell outward -- so that the exiting gas will travel faster than the speed of sound. The video is correct in saying that the speed of sound is the maximum possible velocity within the neck. You are also correct in stating that higher than the speed of sound is possible for the nozzle as a whole -- but only if the nozzle bells outward after the neck. Compressible fluids like gases act counter-intuitively once they get to the speed of sound. With liquids you can continually increase velocity in the neck by increasing the pressure drop. With gases there is a point called "choked" when you achieve the speed of sound in the neck and then you actually have to expand the nozzle outward to achieve higher speeds.