{"id":171330,"date":"2023-06-05T07:06:09","date_gmt":"2023-06-05T07:06:09","guid":{"rendered":"\/knowledge\/forums\/topic\/i-am-running-a-simulation-in-forte-with-the-spray-model-active-beyond-a-certain-crank-angle-the-simulation-gets-slower-and-slower-timestep-reduction-and-solution-recycling-finally-the-solver-sto\/"},"modified":"2023-07-31T12:30:21","modified_gmt":"2023-07-31T12:30:21","slug":"i-am-running-a-simulation-in-forte-with-the-spray-model-active-beyond-a-certain-crank-angle-the-simulation-gets-slower-and-slower-timestep-reduction-and-solution-recycling-finally-the-solver-sto","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/i-am-running-a-simulation-in-forte-with-the-spray-model-active-beyond-a-certain-crank-angle-the-simulation-gets-slower-and-slower-timestep-reduction-and-solution-recycling-finally-the-solver-sto\/","title":{"rendered":"I am running a simulation in Forte with the spray model active. Beyond a certain Crank Angle, the simulation gets slower and slower (timestep reduction and solution recycling) Finally the solver stops with the error: Error occurred in wallfilm vaporization: The sum of fuel vapor mole fractions is zero at the surface of parcel # … What does this error mean? How can I prevent it from occurring?"},"content":{"rendered":"

The error generally means that the area in the vicinity of the wall film has become flooded with liquid fuel. Usually, this is because the liquid fuel mass flow rate is too high, or because the spray parameters are preventing the droplets from evaporating quickly enough. Setting spray parameters in the absence of experimental data can be very difficult, so this error may be hard to prevent without a change in the modelling approach. The details of the spray are often secondary to the simulation, and spray modelling is quite computationally expensive. Since Forte simulations are already lengthy, a fuel vapor mass flow boundary condition has been introduced at Forte V 19.2 as an alternative to spray injection. The fuel vapor mass flow inlet provides a stable alternative to spray injection for simulations where spray data is insufficient\/not the focus of the analysis. Using the new fuel vapour massflow inlet boundary condition should resolve the error and prevent the solution from recycling at a tiny timestep.<\/p>\n","protected":false},"template":"","class_list":["post-171330","topic","type-topic","status-publish","hentry","topic-tag-19-2","topic-tag-boundary-initial-conditions","topic-tag-fluid-dynamics","topic-tag-forte","topic-tag-inlet-outlet"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t