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Diffstat (limited to '530/CH5/EX5.3.ii/example_5_3ii.sce')
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diff --git a/530/CH5/EX5.3.ii/example_5_3ii.sce b/530/CH5/EX5.3.ii/example_5_3ii.sce new file mode 100755 index 000000000..712bd041e --- /dev/null +++ b/530/CH5/EX5.3.ii/example_5_3ii.sce @@ -0,0 +1,71 @@ +clear;
+clc;
+
+// A Textbook on HEAT TRANSFER by S P SUKHATME
+// Chapter 5
+// Heat Transfer by Forced Convection
+
+
+// Example 5.3(i)
+// Page 215
+printf("Example 5.3(ii), Page 215 \n\n")
+
+D = 0.015 ; // [m]
+V = 1 ; // [m/s]
+Tw = 90 ; // [degree C]
+Tmi = 50 ; // [degree C]
+Tmo = 65 ; // [degree C]
+
+// From Table A.1
+k = 0.656 ; // [W/m K]
+rho = 984.4 ; // [kg/m^3]
+v = 0.497 * 10^-6 ; // [m^2/s]
+Cp = 4178 ; // [J/kg K]
+Pr = 3.12 ;
+rho_in = 988.1 ; // [kg/m^3]
+
+m_dot = %pi*(D^2)*rho_in*V/4 ; // [kg/s]
+
+Re = 4*m_dot/(%pi*D*rho*v) ;
+
+// Using eqn 5.3.2 and 4.6.4a
+f = 0.079*(Re)^-0.25 ;
+
+Nu = (f/2)*(Re-1000)*Pr/[1+12.7*(f/2)^(1/2)*((Pr^(2/3))-1)];
+h = Nu*k/D; // [W/m^2 K]
+
+// From the energy equation, extracting the value of L
+L = m_dot*Cp*(Tmo-Tmi)*[log((Tw-Tmi)/(Tw-Tmo))]/[((Tw-Tmi)-(Tw-Tmo))*h*D*%pi]; // [m]
+
+// (ii)
+printf("\nTrial and error method \n");
+
+// Trial 1
+printf("Trial 1\n");
+printf("Assumed value of Tmo = 70 degree C\n");
+T_mo = 70 ; // [degree C]
+T_b = 60 ; // [degree C]
+
+k1 = 0.659 ; // [W/m K]
+rho1 = 983.2 ; // [kg/m^3]
+v1 = 0.478 * 10^-6 ; // [m^2/s]
+Cp1 = 4179 ; // [J/kg K]
+Pr1 = 2.98 ;
+
+Re1 = 4*m_dot/(%pi*D*rho1*v1);
+
+// From Blasius eqn (4.6.4a), we get
+f1 = 0.005928;
+
+// Substituting this value into the Gnielinski Eqn
+Nu_d = 154.97;
+h = Nu_d*k1/D ; // [W/m^2 K]
+
+// from eqn 5.3.3, we get
+Tmo1 = 73.4 ; // [degree C]
+printf("Value of Tmo obtained = 73.4 degree C\n");
+
+// Trial 2
+printf("Trial 2\n");
+printf("Assume Tmo = 73.4 degree C\n");
+printf("Value of Tmo obtained = 73.6 degree C which is in reasonably close agreement with assumed value.\n")
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