1 files changed, 20 insertions, 0 deletions
diff --git a/51/CH7/EX7.7/7_7.sce b/51/CH7/EX7.7/7_7.sce
new file mode 100755
index 000000000..2106c81c5
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+++ b/51/CH7/EX7.7/7_7.sce
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+clc;
+clear;
+V=240;//mph
+ratio=1/10;
+Vair=240;//mph
+Fm=1;//lb; Fm =drag force on model
+p=14.7;//psia; standard atmospheric pressure
+//Re=Rem
+//(d*V*l/vis)=(dm*Vm*lm/vism)
+//here Vm=V and lm/l=ratio
+//assumption made is that an increase in pressure does not significantly change viscosity
+drat=V/(ratio*Vair);//where drat=dm/d
+//for an ideal gas p=d*R*T
+//T=Tm
+//hence, pm/p=dm/d; pm/p=prat
+pm=p*drat;
+//F/(0.5*d*(V^2)*(l^2))=Fm/(0.5*dm*(Vm^2)*(lm^2))
+F=(1/drat)*((V/Vair)^2)*((1/ratio)^2)*Fm;
+disp("psia",pm,"The required air pressure in the tunnel=")
+disp("lb",F,"The corrosponding drag on the prtotype for a 1 lb drag on the model=")
+\ No newline at end of file