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Diffstat (limited to '3720/CH7/EX7.10')
-rw-r--r-- | 3720/CH7/EX7.10/Ex7_10.sce | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/3720/CH7/EX7.10/Ex7_10.sce b/3720/CH7/EX7.10/Ex7_10.sce new file mode 100644 index 000000000..f8e449a92 --- /dev/null +++ b/3720/CH7/EX7.10/Ex7_10.sce @@ -0,0 +1,37 @@ +//Example 7_10
+clc;clear;
+// Given values
+L_m=0.991;// Length of the model truck in m
+h_m=0.257;// Height of the model truck in m
+w_m=0.159;// Width of the model truck in m
+V_p=26.8;// Velocity of the prototype in m/s
+T=25;// °C
+C=16;// Geometric ratio
+
+// Properties
+//For air at atmospheric pressure and at T=25°C,
+rho_m=1.184;// Density of air in kg/m^3
+mu_m=1.849*10^-5;// Viscosity of air in kg/m.s
+
+// Calculation
+// From table 7.7,
+V_m=[20 25 30 35 40 45 50 55 60 65 70];// Velocity of the model truck in m/s
+F_D=[12.4 19.0 22.1 29.0 34.3 39.9 47.2 55.5 66.0 77.6 89.9];// Drag force of the model truck in N
+for(i=1:11)
+ A_m=w_m*h_m;// Area of the model truck in m^2
+ C_Dm(i)=(F_D(i))/((1/2)*rho_m*(V_m(i))^2*A_m);// Drag coefficient
+ Re_m(i)=(rho_m*V_m(i)*w_m)/(mu_m);// Reynolds number of the model truck
+end
+xlabel('Re*10^-5');
+ylabel('C_D');
+xtitle('FIGURE 7-41');
+plot((Re_m/10^5),C_Dm,'o');
+rho_p=rho_m;// Density of air in kg/m^3
+w_p=w_m;// Width of the prototype in m
+mu_p=mu_m;// Viscosity of air in kg/m.s
+Re_p=(rho_p*V_p*w_p)/(mu_p);// Reynolds number of the prototype
+A_p=A_m;// // Area of the prototype in m^2
+C_Dp=C_Dm(10);// Drag coefficient
+F_Dp=(1/2)*rho_p*V_p^2*C^2*A_p*C_Dp;// Aerodynamic drag on the prototype in N
+printf("The aerodynamic drag on the vehicle=%0.0f N\n",F_Dp);
+// The answer provided in the textbook is wrong
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