{"id":317826,"date":"2023-11-15T15:14:42","date_gmt":"2023-11-15T15:14:42","guid":{"rendered":"\/forum\/forums\/reply\/317826\/"},"modified":"2023-11-15T15:14:42","modified_gmt":"2023-11-15T15:14:42","slug":"317826","status":"publish","type":"reply","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/reply\/317826\/","title":{"rendered":"Reply To: High Mach number and Linear solver overflow fatal error"},"content":{"rendered":"

<p>Thanks for the answer.<\/p><p>Yes I am using MRF, where volute and ported shroud are statinoary, and backspace, impeller and inlet region are rotating, which I connected with mixing plane interface. I tried different physical time step upto low as 2e-6 sec. but it is not working. on the other hand if I dont include backspace then it works, so now I am initialising ‘the complete model’ with converge ‘without backspace model’ and this time I am using local time scale value of 3, as it allows different physical time in different region depending on the speed of the flow. I will update if it works.<\/p><p>By the way I use this speed ramping method and it works for this ‘without backspace model’ but not for ‘with backspace model’, but in this study i used fixed physical time step.<\/p><\/p>\n","protected":false},"template":"","class_list":["post-317826","reply","type-reply","status-publish","hentry"],"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