Mass diffuison coefficient ??

kevin

Dear friend Who can assist me to write the Binary diffusion coefficient ?? Today ,Five species (includes H2,O2,H2O,N2,CO2)be existed inside the my model. but, i never write any UDF about binary diffusion coefficient . so, you can help me to write a simple program about this problem ... ************* you can refer to this book Book Name is Transport Phenomena Author : Bird ,R., Stewart , W., Lighfoot , E., Year : 1966 ****************** P*Dij(x,y)/[(Pc-i*Pc-j)**(1/3)*(Tc-i*Tc-j)**(5/12)*(1/Mi+1/Mj)**1/2] == 3.64*10**(-8)*[Tcell/(Tc-i*Tc-j)**(1/2)]**2.334

Tc-i critical temperature of cell of species i Tc-j critical temperature of cell of species j Pc-i critical pressure of cell of species i Pc-j critical pressure of cell of species j Mi molecular weight of the species i Mj molecular weight of the species j P total pressure Tcell temperature of cell you can use for writing this progrma by DEFINE_DIFFUSIVITY(name,c,t,i) ************************** Best regard

kevin