You have an air compressor capable of supplying 150 SCFM @ 150psi to a wind tunnel. The test section has the following maximumcross-sectional dimensions: Width = 0.5 in, Height = 2.0 in. Whatis the maximum achievable Mach number in the test section and whatare the corresponding dimensions of the throat and test sectionif:

a. The flow discharges directly to the room and is perfectlyexpanded?

b. The flow discharges to the room through a normal shock?

c. The flow discharges to the room through an ideal secondarycontraction?

Please be sure to explain.

HINTS:

1. SCFM = standard cubic feet per minute. This iseffectively a mass flow rate because it specifies volume flow rateat a specific density - the density of (air here) at \'standard\'conditions. To get mass flow rate (in lb/min) multiply SCFMby the density of air at standard conditions. Note that Istrongly recommend converting SCFM to SI units (standard cubicmeters per minute) first and then working the problem fromthere.

2. Air compressors\' performance is reported as GAGEpressure. This means that you will need to add 14.7 psi tothe rated output of the air compressor (150 psi) to get absolutepressure which is what you should be using in yourcalculations.

3. Assume that the temperature of the air upstream of the tunnelcontraction is 273K. While the air compressor systemdoes have an aftercooler, this is probably unrealisticallylow. Nevertheless, it is what I assumed in the solution andyou should too. One thing that would be interesting to lookat (but not required) is to see how your answers change if thetemperature upstream of the tunnel contraction is higher (say300K).