//clear// clear; clc; //Example 9.6 //Given Dt = 2; //[m] Da = 0.667; //[m] n = 180/60; //[rps] T = 20; //[C] qg = 100; //[m^3/h] rho = 1000; //[kg/m^3] mu = 10^-3; //[kg/m-s] ut = 0.2; //[m/s] //(a) //The power input is calculated and followed by correction of gas effect Nre = n*Da^2*rho/mu; //For a flat blade turbine, from Table 9.3 KT = 5.75; //Using Eq.(9.24) Po = KT*n^3*Da^5*rho/1000; //[kW] At = %pi/4*Dt^2; //[m^2] //Superficial gas velocity Vs_bar = At*qg/3600/10 //[m/s] //From Fig. 9.20 Pg/Po = 0.60 Pg = Po*0.6; //[kW] //From Fig.9.7, depth of liquid is equal to diameter of the tank //Hence, liquid volume V = %pi/4*Dt^2*Dt; //[m^3] //The input power per unit volume PgbyV = Pg/V ; //[kW/m^3] //(b) sigma = 72.75; //[g/s^2] rho_L = 10^-3; //[g/mm] PgbyV = PgbyV*10^3 ; //[g/mm-s^2] //Using Eq.(9.46) //Let x = shi^(0.5) //solving the equation as quadratic equation a = 1; b = -(Vs_bar/ut)^0.5; c = -0.216*((PgbyV)^0.4)*(rho_L^0.2)/(sigma^0.6)*(Vs_bar/ut)^(0.5); x = (-b+sqrt(b^2-4*a*c))/(2*a); shi = x^2; //(c) //To find out mean bubble diameter //Using Eq.(9.44) Ds_bar = 4.15*sigma^0.6/(PgbyV^0.4*rho_L^0.2)*shi^0.5+0.9 // [mm] //(d) //From Eq.(9.40) aprime = 6*shi/Ds_bar //[mm^-1]