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clc
// Example 4.9.py
// Consider the arrangement shows in fig. 4.29. A 15 degree half angle diamond
// wedge airfoil is in supersonic flow at zero angle of attack. A pitot tube is
// inserted into the flow at the location shown in fig 4.29. The pressure measured
// by the Pitot tube is 2.596 atm. At point a on the backface, the pressure is 0.1
// atm. Calculate the freestream Mach number M1.
//
// Variable declaration
theta = 15.0 // wedge angle/deflection (in degrees)
po4 = 2.596 // measured pressure (in atm)
p3 = 0.1 // pressure at point a (in atm)
// Calculations
po4_by_p3 = po4/p3
// from Table A 2 for po4/p3 = 25.96
M3 = 4.45
v3 = 71.27
v2 = v3 - 2*theta
// from Table A 5, for v2 = 41.27 degrees
M2 = 2.6
// Mn2 = M2*sin((beta1-theta)*%pi/180) @equation 1
// Guessing
// Guess 1
M1 = 4.0 // Guess for freestream number
beta1 = 27.0 // from fig 4.5 (in degrees)
Mn1 = M1*sin(beta1*%pi/180) // mach number normal to shock
// from Table A2 for Mn1 = 1.816
Mn2 = 0.612
// but Mn2 from equation 1 is 0.54
// Guess 2
M1 = 4.5 // Guess for freestream number
beta1 = 25.5 // from fig 4.5 (in degrees)
Mn1 = M1*sin(beta1*%pi/180) // mach number normal to shock
// from Table A2 for Mn1 = 1.937
Mn2 = 0.588
// but Mn2 from equation 1 is 0.47
// Guess 3
M1 = 3.5 // Guess for freestream number
beta1 = 29.2 // from fig 4.5 (in degrees)
Mn1 = M1*sin(beta1*%pi/180) // mach number normal to shock
// from Table A2 for Mn1 = 1.71
Mn2 = 0.638
// but Mn2 from equation 1 is 0.638
// Result
printf("\n Freestream mach number is %.1f", M1)
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