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clear;
clc;
printf("\t Example 11.16\n");
T1=298; //temp.of air,K
T2=323.15; //film temp.,K
x=0.05; //mass fraction of water at 75 C
Gm=0.017; //average mass transfer coefficient,kg/(m^2*s)
A=0.04; //suraface area of pan,m^2
l=0.2; //length of pan in flow direction,m
v=5; //air speed,m/s
m=(x+0.277)/2; //film composition of water at 50 C
Mf=26.34; //mixture molecular weight,kg/kmol
af=101325*Mf/(8314.5*T2); //film density from ideal gas law,kg/m^3
Uf=1.75*10^-5; //film viscosity,kg/(m*s)
Vf=Uf/af; //kinematic viscosity,m^2/s
Rel=v*l/Vf; //reynolds no. comes out to be 56,800 so the flow is laminar.
B=0.314; //mass transfer driving force
D=2.96*10^-5; //diffusivity of water in air,m^2/s
Sc=Vf/D; //scimidt no.
Nu=0.664*Rel^0.5*Sc^1/3; //nussselt no.
Gmw1=Nu*(D*A/l); //appropriate value of mass transfer gas phase coeffficient of water in air,kg/(m^2*s)
Gmw=Gmw1*(log(1+B)/B)+0.0168; //mass transfer gas phase coeffficient of water in air,kg/(m^2*s)
printf("mass transfer gas phase coeffficient of water in air is : %.4f kg/(m^2*s)\n In this caes, the blowing factor is 0.870. thus the mild blowing has reduced the mass transfer coefficient by about 13 percent.",Gmw);
//end
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