//Chapter-11, Example 11.3, Page 481 //============================================================================= clc clear //INPUT DATA D=0.0016;//Diameter of the wire in m T=255;//Temperature difference in degree C p1=957.9;//Density of liquid in kg/m^3 Cpl=4640;//Specific heat in J/kg.K u=(18.6*10^-6);//Dynamic viscosity in N.s/m^2 hjg=2257;//Enthalpy in kJ/kg k=(58.3*10^-3);//Thermal conductivity in W/m.K pv=31.54;//Density of vapour in kg/m^3 Ts=628;//Surface temperature in K Tsat=373;//Saturation temperature in K //CALCULATIONS hc=(0.62*((k^3*pv*(p1-pv)*9.81*((hjg*1000)+(0.4*Cpl*T)))/(u*D*T))^0.25);//Convective heat transfer coefficient in W/m^2.K hr=((5.67*10^-8)*(Ts^4-Tsat^4))/(Ts-Tsat);//Radiative heat transfer coefficient in W/m^2.K hm=(hc+(0.75*hr));//Mean heat transfer coefficient in W/m^2.K Q=(hm*3.14*D*T)/1000;//Power dissipation rate per unit length of the heater in kW/m //OUTPUT mprintf('Mean heat transfer coefficient is %3.1f W/m^2.K \nPower dissipation rate per unit length of the heater is %3.3f kW/m',hm,Q) //=================================END OF PROGRAM==============================