For the inlet conditions of Example 6.2, what is the maximum length of pipe that may be used if the pipe is 2 in. in diameter? What is it for the inlet conditions of Example 6.3?

EXAMPLE 6.2

EXAMPLE 6.1

 

EXAMPLE 6.3
 

Air flows from a reservoir through an isentropic nozzle into a long. straight pipe. The pressure and temperature in the reservoir are 20 atm and 1,000R (555.6 K), respectively, and the Mach number at the entrance of the pipe is 0.05. (a) What is the value of f Lmax/"H? (b) What are the pressure, temperature, density, lin- ear velocity, and mass velocity when L, = Lma? (c) What is the mass velocity when fLmax /"H = 400? Solution (a) Values for substitution in Eq. (6.45) are y = 1.4 and Ma, = 0.05. Then jLmax 1 1.4 0.052 1.4 +1 1 2{1+[(1.4 1)/2]0.052} In = 280 (1.4 + 1)0.052