# udf and uds for transport equation

 Register Blogs Members List Search Today's Posts Mark Forums Read

 September 10, 2013, 02:56 udf and uds for transport equation #1 New Member   Jack Chung Join Date: Mar 2013 Posts: 3 Rep Power: 5 Hello, every body My geometry is a 2D suqare enclosure and the fluid fill of inside is Al2O3-Water. This case is a natural convection and consider the transport equation include the brownian motion and thermophoresis mechanism. Because i don't have enough experiences to validation the nanoparticle rayleigh number and nusselt number. should i click the multiphase or discrete phase in models ? Can any one can help me to solve it. thanks the transport equation source is u*(Partial phi/Partial x) + v*(Partial phi/Partial y) =[(Partial/Partial x)*(DB*Partial phi/Partial x)+(Partial/Partial y)*(DB*Partial phi/Partial y]+[(Partial/Partial x)*(DT*Partial T/Partial x)+(Partial/Partial y)*(DT*Partial T/Partial y] DB is brownian motion&DT is thermophoresis coefficient by the way this is my code(the transport equation source term)困惑： #include "udf.h" DEFINE_SOURCE(temperature_source,c,t,dS,eqn) { real x[ND_ND]; real source; real D_T /* thermophoresis coefficient */ real S_T; /* thermophoresis parameter */ real mu_f; /* water of dynamic viscosity Unit: kg/m-s */ real rho_f; /* water of density Unit: kg/m^3 */ real T; /* Temperatur of cold wall Unit: kelvin scale */ real phi; /* nanoparticle volume fraction */ S_T = 0.13; mu_f = 0.00063544; rho_f = 991.8; T = 313; phi = 0.01; C_CENTROID(x,c,t); C_UDSI(c,t,1); C_T_G(c,t)[1]; /* returns the x-component of the cell temperature gradient vector */ D_T = S_T*(mu_f/(rho_f*T))*phi; C_T_G(c,t,i)= c_t_g(c,t,i)/dx + ds[equ] = D_T*C_UDSI(c,t,0); return source; }

 September 15, 2015, 01:02 question #2 Member   Join Date: Nov 2014 Posts: 42 Rep Power: 3 Hi I want to use one user defined scalar for transport equation (for volume fraction of nano particle), I set in fluent but I dont know how I specified that scalar quantity is volume fraction? I would appreciate if you can help me.

 Thread Tools Display Modes Linear Mode

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post borhan_sd@yahoo.com Fluent UDF and Scheme Programming 0 July 15, 2013 03:32 tompa Fluent UDF and Scheme Programming 2 November 28, 2010 23:57 pifou74 FLUENT 0 September 29, 2009 16:02 Bharath FLUENT 0 December 1, 2006 16:58 T.K. Yang FLUENT 0 May 9, 2006 02:54

All times are GMT -4. The time now is 15:20.