//Chapter-5, Example 5.8, Page 177 //============================================================================= clc clear //INPUT DATA x=0.2;//Diatance of plane from the wall in m t=10;//Time for heat flow in h T=[25,800];//Initial and final tempertaure in degree C k=0.8;//Thermal conductivity in W/m.K a=0.003;//Thermal diffusivity in m^2/h //CALCULATIONS X=(x*(2*sqrt(a*k)));//Calculation of X for erf function Y=0.585;//Taking ref(0.577)=0.585 from table 5.1 on page no. 175 Ti=T(2)-((T(2)-T(1)))*Y;//Temperarture of the plane in degree C Qi=((-k*(T(1)-T(2))*exp(-x^2/(4*a*t)))/(sqrt(3.14*a*t)));//Instanteneous heat flow rate per unit area in W/m^2 Q=((2*k*(T(2)-T(1))*3600)/(sqrt((3.14*a)/t)))/10^8;//Total heat energy taken up by the wall in 10 hours in J/m^2 //OUTPUT mprintf('Temperarture of the plane is %3.2f degree C\nInstanteneous heat flow rate per unit area is %i W/m^2\nTotal heat energy taken up by the wall in 10 hours is %3.3f*10^8 J/m^2',Ti,Qi,Q) //=================================END OF PROGRAM==============================