Bug 4565 describes incorrect application of temperature and quality boundary conditions during transient events, causing wrong enthalpies with the non-iterative transient solver for two-phase fluids and mixtures. The iterative solver fails to converge for two-phase and non-condensable mixtures, though it works for pure two-phase fluids. The issue was fixed in version 8.15.0.5062. The workaround is to use pressure and quality boundary conditions instead.
ERROR INFORMATION
Bugzilla Error Number | BUG 4565 |
Description of Error | Temperature and quality and quality only boundary conditions are not applied correctly during transient events. This leads to incorrect enthalpies being applied on these nodes when selecting the non-iterative transient solver with both pure two-phase fluids as well as mixtures of a two-phase fluid with noncondensable gas(es). When selecting the iterative transient solver with a two-phase and non-condensable mixture, convergence of the energy solution is not obtained. The case for a pure two-phase fluid works correctly with this solver selection. |
Comments | The specific combinations of boundary conditions are not applied correctly. The quality was ignored in both cases. |
First Incorrect Version | 8.0.11 | Corrected Version | 8.15.0.5062 |
Workaround Description: Specify a pressure and quality boundary condition instead. For Azeotropic two phase fluid, the relation between temperature and pressure is unambiguous; thus, a 100% equivalent boundary condition can be established using a pressure instead of a temperature in conjunction with a quality as a two-phase boundary condition. |