Calculate air flow rate given compressed air pressure and pipe size
Thread Content
Fellow sailors, please help me answer this question: Given that the pressure of the compressed air is 0.4 MPa and the pipe diameter is DN50, can we determine the flow rate at the exhaust outlet at a depth of 9 meters below the liquid surface (water)?
Q = 0.82 × SQRT(2 × (P – p_water·g·h – P0)) / p_air) × A = 0.82 × SQRT(2 * (400,000 – 1000 * 10 * 9 – 100,000)) / (1.29 × 4) × 3.14 × 0.05 × 0.05 / 4 × 3600 = 4674 m³/h. This is an estimated value; it’s not certain whether the calculation is correct. I hope experts can provide guidance
I didn’t calculate it that way; the air flow speed I checked was 12–15 meters per second. Then Q=SV=120 m3/h. Is the result we’ve obtained a bit too different?
I don’t think it can be simply determined using flow rate. It is necessary to know the pipe length and the number of fittings, and then calculate the flow rate based on the pressure drop.
I agree with this person’s view; it’s essential to know what the pressure drop is, otherwise the values can vary significantly! !
You can take a look; the first part of the formula I gave is one used to calculate flow velocity based on pipe length and pressure drop. It’s just not clear whether this formula applies to gases. I found it in a textbook on hydraulic design.
Okay, thank you for your help. .