Question

The stagnation chamber of a wind tunnel is connected to a high-pressure airbottle farm which is outside the laboratory building. The two are connectedby a long pipe of 4-in inside diameter. If the static pressure ratio between thebottle farm and the stagnation chamber is 10, and the bottle-farm staticpressure is 100 atm, how long can the pipe be without choking? Assumeadiabatic, subsonic, one-dimensional flow

Answer 1

This question is not complete, the complete question is;

The stagnation chamber of a wind tunnel is connected to a high-pressure air bottle farm which is outside the laboratory building. The two are connected by a long pipe of 4-in inside diameter. If the static pressure ratio between the bottle farm and the stagnation chamber is 10, and the bottle-farm static pressure is 100 atm, how long can the pipe be without choking? Assume adiabatic, subsonic, one-dimensional flow with a friction coefficient of 0.005

Answer:

the length of the pipe is 11583 in or 965.25 ft

Explanation:

Given the data in the question;

Static pressure ratio; p1/p2 = 10

friction coefficient f = 0.005

diameter of pipe, D =4 inch

first we obtain the value from FANN0 FLOW TABLE for pressure ratio of ( p1/p2 = 10 )so

4fL$_{max}$ / D = 57.915

we substitute

(4×0.005×L$_{max}$) / 4  = 57.915

0.005L$_{max}$ = 57.915

L$_{max}$ = 57.915 / 0.005

L$_{max}$  = 11583 in

Therefore, the length of the pipe is 11583 in or 965.25 ft