- **CFX**
(*http://www.cfd-online.com/Forums/cfx/*)

- - **Real Gas table generation**
(*http://www.cfd-online.com/Forums/cfx/134380-real-gas-table-generation.html*)

Real Gas table generationHi all
i have usual problem when i simulate real gas flow, peng-robinson or RK model. this problem is " temperature and absolute pressure table range". for some absolute and pressure range solver diverged and return errors like: Newtons method failed to converge in 100 iterations. This | | occurred while computing the following variable: | | | | Variable Name : Total Temperature | | Location Name : NOZZLE | | Mesh location : VERTICES | | Mesh entity : | | Last 3 Changes : 1.73755E+01 1.71344E+01 1.70618E+01 | | Tolerance : 1.0000E-02 | | | | The Newton iteration was either slowly converging or has stalled. | | The solver will continue with the variable set as it was on the | | final iteration. If this situation continues you might try | | increasing the number of iterations allowed for Newtons method. | | This can be changed by setting one of the parameters: | | | | Temperature : "Constitutive Relation Iteration Limit" | | Pressure : "Newton Pressure Iteration Limit" | | | | for your mixture using the definition file editor. | +--------------------------------------------------------------------+ i generate this range by try and error! is there any relation for set this ranges? Best regards |

These sort of errors are common with complex equations of state. You need to improve your simulation's numerical stability. You can do this by:
* Better mesh quality * Better initial conditions * double precision numerics * smaller time steps * lower order differencing in space and/or time (this one will reduce the accuracy of your simulation) |

All times are GMT -4. The time now is 03:32. |