//Chapter-7, Example 7.3, Page 282 //============================================================================= clc clear //INPUT DATA Ta=20;//Temperature of air in degree C v=3;//Velocity of flow in m/s L=2;//Length of plate in m W=1;//Width of plate in m x1=0.3;//Initial point of the boundary layer in m x2=0.8;//Final point of the boundary layer in m p=1.17;//Density of air at 20 degree C in kg/m^3 k=(15*10^-6);//Kinematic viscosity in m^2/s Re=(5*10^5);//Reynolds number at the transition frm laminar to turbulant //CALCULATIONS x=(k*Re)/v;//Critical length in m Rel=(v*L)/k;//Reynolds number q=(4.64*L)/sqrt(Rel)*1000;//Boundary layer thickness at the trailing edge of plate in mm ts=1.292*(0.5*p*v^2)*sqrt(1/Rel);//Average shear stress in N/m^2 F=(2*L*ts);//Drag force on the two sides of the plate in N q80=(4.64*x2)/sqrt((v*x2)/k);//Boundray layer thickness at x=0.8 m q30=(4.64*x1)/sqrt((v*x1)/k);//Boundray layer thickness at x=0.3 m m=((5/8)*p*v*(q80-q30))/10^-3;//Mass flow of air in kg/s //OUTPUT mprintf('Boundary layer thickness at the trailing edge of plate is % 3.2f mm \nDrag force on the two sides of the plate is %3.4f N \nMass flow of air is %3.1f*10^-3 kg/s',q,F,m) //=================================END OF PROGRAM==============================