# LBM- Nanofluid

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 April 3, 2017, 02:05 LBM- Nanofluid #1 New Member   Arun Sathiyamoorthi Join Date: Apr 2017 Posts: 3 Rep Power: 8 Hi everyone, I am working Lattice boltzmann method. Recently i faced some problems in that. currently im working in nanofluids. i have calculated all the properties using the respected equations and calculated Rayleigh number and Prandtl number for nanofluids. I have used these two in my coding but im not getting the correct ans. Someone kindly help me. double rhonf = ((1-phi)*rhof)+(phi*rhop); double betanf = (rhobetanf/rhonf); double munf = muf/pow((1-phi),2.5); double ks = ( kp+2*kf-2*phi*(kf-kp))/(kp+2*kf+phi*(kf-kp)); double knf = ks*kf; double Prnf = (munf*cpnf) /(knf); double Ranf = (rhobetanf*kf*rhocpnf*muf*Ra)/ (rhof*betaf*knf*rhof*Cpf*munf); double visco = NY*Ma*(1/sqrt(3)*(sqrt(Prnf/Ranf))); double rho0 = 6.0; double alpha = visco/Prnf; double omega = 1.0/((3.0*visco)+0.5); double omegat =1.0/((3.0*alpha)+0.5); double gbeta = Ranf*visco*visco/(float(NX*NX*NX)*Prnf); double rhocpnf = ((1-phi)*(rhof*Cpf))+(phi*rhop*Cpp); double cpnf = (rhocpnf/rhonf); double rhobetanf = ((1-phi)*(rhof*betaf))+(phi*rhop*betap); double betanf = (rhobetanf/rhonf); double munf = muf/pow((1-phi),2.5); double ks = ( kp+2*kf-2*phi*(kf-kp))/(kp+2*kf+phi*(kf-kp)); double knf = ks*kf; double Prnf = (munf*cpnf) /(knf); double Ranf = (rhobetanf*kf*rhocpnf*muf*Ra)/ (rhof*betaf*knf*rhof*Cpf*munf); double visco = NY*Ma*(1/sqrt(3)*(sqrt(Prnf/Ranf))); double rho0 = 6.0; double alpha = visco/Prnf; double omega = 1.0/((3.0*visco)+0.5); double omegat =1.0/((3.0*alpha)+0.5); double gbeta = Ranf*visco*visco/(float(NX*NX*NX)*Prnf);

November 27, 2018, 09:47
#2
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Med oumza
Join Date: Nov 2015
Posts: 4
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Quote:
 Originally Posted by @arun Hi everyone, I am working Lattice boltzmann method. Recently i faced some problems in that. currently im working in nanofluids. i have calculated all the properties using the respected equations and calculated Rayleigh number and Prandtl number for nanofluids. I have used these two in my coding but im not getting the correct ans. Someone kindly help me. double rhonf = ((1-phi)*rhof)+(phi*rhop); double betanf = (rhobetanf/rhonf); double munf = muf/pow((1-phi),2.5); double ks = ( kp+2*kf-2*phi*(kf-kp))/(kp+2*kf+phi*(kf-kp)); double knf = ks*kf; double Prnf = (munf*cpnf) /(knf); double Ranf = (rhobetanf*kf*rhocpnf*muf*Ra)/ (rhof*betaf*knf*rhof*Cpf*munf); double visco = NY*Ma*(1/sqrt(3)*(sqrt(Prnf/Ranf))); double rho0 = 6.0; double alpha = visco/Prnf; double omega = 1.0/((3.0*visco)+0.5); double omegat =1.0/((3.0*alpha)+0.5); double gbeta = Ranf*visco*visco/(float(NX*NX*NX)*Prnf); double rhocpnf = ((1-phi)*(rhof*Cpf))+(phi*rhop*Cpp); double cpnf = (rhocpnf/rhonf); double rhobetanf = ((1-phi)*(rhof*betaf))+(phi*rhop*betap); double betanf = (rhobetanf/rhonf); double munf = muf/pow((1-phi),2.5); double ks = ( kp+2*kf-2*phi*(kf-kp))/(kp+2*kf+phi*(kf-kp)); double knf = ks*kf; double Prnf = (munf*cpnf) /(knf); double Ranf = (rhobetanf*kf*rhocpnf*muf*Ra)/ (rhof*betaf*knf*rhof*Cpf*munf); double visco = NY*Ma*(1/sqrt(3)*(sqrt(Prnf/Ranf))); double rho0 = 6.0; double alpha = visco/Prnf; double omega = 1.0/((3.0*visco)+0.5); double omegat =1.0/((3.0*alpha)+0.5); double gbeta = Ranf*visco*visco/(float(NX*NX*NX)*Prnf);
Dear @arun

I am using alos LBM to simulate the nanofluids behaviour. But, I have a problem with in physical units conversion to the lattice ones. Thank you a lot if you can help me