[Weiqiang Liu]

Hi all,

I am doing a non-equilibrium thermal porous media combustor simulation with fluent. The whole model is implemented with UDF and UDS.

The energy equation of solid is solved with an UDS equation. Source term of solid and fluid energy equation is defined by DEFINE_SOURCE macro.

diffusivity of UDS equation is defined by DEFINE_DIFFUSIVITY macro. thermal conductivity of fluid is modified by DEFINE_PROPERTY macro.

The whole model can run. However, results are not very reasonable. In specific, reactions don't happen at all. I can share my code here. Can anybody give me some suggestions?

Best regards

[Jingyu Cao]

I have the same question, we can chat on wechat. VX:cao460335760

[yf70512]

I am trying to modify the source term of energy equation in non-equilibrium thermal model by UDS and UDF (DEFINE_SOURCE macro).
But the Fluent crashed when the code runned with the error "999999:mpt_accept:error: accept failed: No error". My code is as following:

DEFINE_SOURCE(Fluid_source,c,t,dS,eqn)
{

real Tf, Ts;
real hfs = HFS_CONSTANT; // Placeholder value for heat transfer coefficient
real Afs = AFS_CONSTANT; // Placeholder value for interfacial area density
real source;

// Obtain fluid and solid temperatures
Tf = C_T(c, t); // Fluid temperature
Ts = C_STORAGE_R(c, t, SV_T_S); // Solid temperature

// Obtain hfs and Afs from Fluent's internal calculations
// hfs = C_STORAGE_R(c, t, SV_HFS); // Interfacial heat transfer coefficient
// Afs = C_STORAGE_R(c, t, SV_AFS); // Fluid-solid interfacial area per unit volume

// Calculate the source term based on the modified expression
source = hfs * Afs * (pow(Ts, 4.0) - pow(Tf, 4.0));

// Set the derivative of the source term with respect to Tf
dS[eqn] = 4.0 * hfs * Afs * pow(Ts, 3.0) - 4.0 * hfs * Afs * pow(Tf, 3.0);

return source;

}


DEFINE_SOURCE(Solid_source,c,t,dS,eqn)
{

real Tf, Ts;
real hfs = HFS_CONSTANT; // Placeholder value for heat transfer coefficient
real Afs = AFS_CONSTANT; // Placeholder value for interfacial area density
real source;

// Obtain fluid and solid temperatures
Ts = C_STORAGE_R(c, t, SV_T_S); // Solid temperature
Tf = C_T(c, t); // Fluid temperature

// Obtain hfs and Afs from Fluent's internal calculations
// hfs = C_STORAGE_R(c, t, SV_HFS); // Interfacial heat transfer coefficient
// Afs = C_STORAGE_R(c, t, SV_AFS); // Fluid-solid interfacial area per unit volume

// Calculate the source term based on the modified expression
source = hfs * Afs * (pow(Tf, 4.0) - pow(Ts, 4.0));

// Set the derivative of the source term with respect to Tf
dS[eqn] = 4.0 * hfs * Afs * pow(Tf, 3.0) - 4.0 * hfs * Afs * pow(Ts, 3.0);

return source;

}

I am not sure if it was caused by the wrong expreesion of reading the solid temperature. Could you please give me some suggestions? I would be very grateful if you could share your code with me. My VX is YuF__0306.