//example 4.15 a/if P1-P2 ((1.019-1.01)*10^5) in example 4.14 is doubled what is the flow velocity in test section?b/if contraction ratio A1/A2 (2/.5) is doubled then what is the flow velocity in test section?
V=40; //initial velocity in test section,m/s
r=4; // A1/A2=2/0.5=4 
R=8 ;//doubled value of A1/A2
Dp=(1.019-1.01)*10^5; //intial value of pressure difference
D=1.23; //density,Kg/m^3