In transonic wind tunnel testing, the small area decrease causedby placing the model in the test section, i.e., by the modelblockage, can cause relatively large changes in the flow in thetest section. To illustrate this effect, consider a tunnel that hasan empty test section Mach number of 1.08. The test section has anarea of 1 m2 and the stagnation temperature of the air flowingthrough the test section is 25°C. If a model with a cross-sectionalarea of 0.005 m2 is placed in this test section,find the percentagechange in test section velocity. Assume one-dimensional isentropicflow.
