View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0000434 | OpenFOAM | Bug | public | 2012-02-23 21:13 | 2012-02-24 12:27 |
| Reporter | Assigned To | henry | |||
| Priority | low | Severity | text | Reproducibility | always |
| Status | resolved | Resolution | fixed | ||
| Platform | Linux | OS | Ubuntu | OS Version | 10.04 |
| Summary | 0000434: Porous media, power-law model, error in the description formula in porousZone.C | ||||
| Description | In the file porousZone.H it states that the power-law model of porous media is implemented using the following equation: S = - \rho C_0 |U|^{(C_1 - 1)/2} U but then, in the file porousZoneTemplate.C the member function that adds the resistance of the porous media in explicit and implicit form is: Udiag[cells[i]] += V[cells[i]]*rho[cells[i]]*C0*pow(magSqr(U[cells[i]]), C1m1b2); AU[cells[i]] = AU[cells[i]] + I*(rho[cells[i]]*C0*pow(magSqr(U[cells[i]]), C1m1b2)); where C1m1b2 is (C_1-1)/2. We can see that it uses magSqr instead of mag to obtain the magnitude of velocity. I have obtained the coefficients for both Power-law (using the formula given in the description in porousZone.H) and Darcy-Forchheimer, and simulated them with an grid independent mesh; the results of Darcy are almost the same as the hand calculations, whereas the Power-law is much smaller. Changing magSqr to mag it gives values almost the same as hand calculations (always following the formula given in porousZone.H). On the other hand, reading the implementation in Fluent of this power-law (https://www.sharcnet.ca/Software/Fluent12/html/ug/node233.htm) and in literature, I deduce that the formula given in the description of porousZone.H is erroneous, it should be: S = - \rho C_0 {|U|^2}^{(C_1 - 1)/2} U thus, the equation used in the member function is the correct one. Using the latter equation to obtain the coefficients gives the correct result in the simulations. | ||||
| Tags | No tags attached. | ||||
