//Kunii D., Levenspiel O., 1991. Fluidization Engineering(II Edition). Butterworth-Heinemann, MA, pp 491 //Chapter-7, Example 5, Page 181 //Title: Comparing Predictions for k* //========================================================================================================== clear clc //INPUT rhog=1.217;//Density of gas in kg/m^3 myu=1.8E-5;//Viscosity of gas in kg/m s umf=0.11;//Velocity at minimum fluidization condition in m/s rhos=2000;//Density of solid in kg/m^3 uo=1.0;//Superficial gas velocity in m/s g=9.80;//Acceleration due to gravity in m/s^2 dp=[30;40;50;60;80;100;120];//Diameter of particle in micrometer uti=[0.066;0.115;0.175;0.240;0.385;0.555;1.0];//Terminal velocity of particles in m/s //CALCULATION n=length(dp); i=1; while i<=n //Using Yagi & Aochi's correlation Ret(i)=(rhog*(uti(i))*dp(i)*10^-6)/myu; kistar1(i)=((myu*((uo-uti(i))^2))/(g*(dp(i)*10^-6)^2))*(0.0015*(Ret(i)^0.5)+(0.01*(Ret(i)^1.2))); //Using Wen & Hasinger's correlation kistar2(i)=(((1.52E-5)*((uo-uti(i))^2)*rhog)/(g*dp(i)*10^-6)^0.5)*(Ret(i)^0.725)*((rhos-rhog)/rhog)^1.15; //Using Merrick & Highley's correlation kistar3(i)=uo*rhog*(0.0001+130*exp(-10.4*((uti(i)/uo)^0.5)*((umf/(uo-umf))^0.25))); //Using Geldart's correlation kistar4(i)=23.7*uo*rhog*exp(-5.4*(uti(i)/uo)); //Using Zenz & Weil's procedure x1(i)=(uo^2)/(g*(dp(i)*10^-6)*rhos^2);//Computation of value of x-axis for Fig.(6), page 175) y1=[12.2;8.6;6.4;4.9;2.75;1.8;1.2];//Value of y-axis corresponding to each value of x-axis kistar5(i)=y1(i)*rhog*uo; //Using Gugnoni & Zenz's procedure x2(i)=(uo-uti(i))/((g*dp(i)*10^-6)^0.5);//Computation of value of x-axis for Fig.(6), page 175) y=[5.8;5.4;3.2;2.8;1.3;0.6;0];//Value of y-axis corresponding to each value of x-axis kistar6(i)=y(i)*rhog*uo; i=i+1; end i=1; printf('dp(micrometer)'); printf('\tYagi & Aochi'); printf('\tWen & Hashinger'); printf('\t\tMerrick & Highley'); printf('\tGeldart et al.'); printf('\t\tZenz & Well'); printf('\t\tGugnoni & Zenz'); while i<=n mprintf('\n%f',dp(i)); mprintf('\t%f',kistar1(i)); mprintf('\t%f',kistar2(i)); mprintf('\t\t%f',kistar3(i)); mprintf('\t\t%f',kistar4(i)); mprintf('\t\t%f',kistar5(i)); mprintf('\t\t%f',kistar6(i)); i=i+1; end //Note: There is huge deviation of the calculated answer and the answer given in the textbook for the correlation of Merrick & Highley. There is a contradiction in the correlation used in the problem and the one given in page 179. //We tried to retrieve the original paper i.e. D.Merrick and J.Highley, AICHE J., 6, 220(1960). But the effort was not fruitful. //====================================END OF PROGRAM ====================================================