Hi, when I run my Microflow simulation all the curves are going dow to converge but suddenly somewhere near the 200 iteration they "jump" high and fall in a completely vertical line towards the residual and then is written that the simulation is completed. The results of course appear all in black.
Why is this happening? Any advice of how to solve this?
Thank you in advance
Run completed before time
Re: Run completed before time
When the residuals plummet to the convergence criteria (default at 10-5) and then flatline it is because the solution has diverged.
In 99% of cases this is due to a poor mesh with high aspect ratio cells. The best two ways to get around this is to
1) add more cells
2) simplify the geometry to reduce the grid constraints
Any geometry adds constraints on the grid as a grid line has to lie along each surface in the model. For example, if you have one window sill on one wall at 1m high and on another wall at 1.001m high there has to be a cell between 1m and 1.001m and so if your default mesh size is 0.1m you aspect ratio will be 0.001:0.1 or 1 to 100. So make sure you align your windows in this example.
In 99% of cases this is due to a poor mesh with high aspect ratio cells. The best two ways to get around this is to
1) add more cells
2) simplify the geometry to reduce the grid constraints
Any geometry adds constraints on the grid as a grid line has to lie along each surface in the model. For example, if you have one window sill on one wall at 1m high and on another wall at 1.001m high there has to be a cell between 1m and 1.001m and so if your default mesh size is 0.1m you aspect ratio will be 0.001:0.1 or 1 to 100. So make sure you align your windows in this example.