//Exa 5.1 clc; clear; close; //given data format('v',9) rho=1.14;// in kg/m^3 k=2.73*10^-2;// in W/mK Cp=1.005;// in kg/kgK v= 16*10^-6;// in m^2/s Pr=0.67; // Other data given in the problem are V=2;// in m/s w=20*10^-2;// in m t_infinite= 10;// in degree C t_s=65;// in degree C x=0.25;// in m from leading edge // Re= rho*Vx/miu = V*x/v Re= V*x/v; //Since Re<5*10^5 , hence the flow is a laminar flow //(a) Boundary layer thickness delta= 5*x/(sqrt(Re));// in m delta=delta*10^2;// in cm disp(delta,"Boundary layer thickness in cm") //(b) Thermal boundary layer thickness delta_t= delta/Pr^(1/3);// in cm disp(delta_t,"Thermal boundary layer thickness in ch") //(c) Local friction coefficient Cfx= 0.664/sqrt(Re); disp(Cfx,"Local friction coefficient"); Cf=2*Cfx; disp(Cf,"Average friction coefficient"); //(d) Total drag force A=.25*.2;// in m^2 toh_o=Cf*(rho*V^2/2); F=toh_o*A; disp(F,"Total drag force in N"); //(e) // Formula Nux= hx*x/k = 0.332*Re^(1/2)*Pr^(1/3) hx= 0.332*k/x*Re^(1/2)*Pr^(1/3);// in W/m^2K disp(hx,"Local heat transfer coefficient in W/m^2K") h=2*hx; disp(h,"Average heat transfer coefficient in W/m^2K") //(f) q=h*A*(t_s-t_infinite); disp(q,"Rate of heat transfer in W/m^2K"); //Note: In the book, they calculated wrong value of Re so all the answer in the book is wrong