{"id":382404,"date":"2024-09-11T19:26:07","date_gmt":"2024-09-11T19:26:07","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/icfd-extremely-high-and-constant-drag-pressure-forces\/"},"modified":"2024-09-16T12:09:36","modified_gmt":"2024-09-16T12:09:36","slug":"icfd-extremely-high-and-constant-drag-pressure-forces","status":"answered","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/icfd-extremely-high-and-constant-drag-pressure-forces\/","title":{"rendered":"ICFD Extremely high and constant drag pressure forces"},"content":{"rendered":"

<p>Hello,<br><br>I am running an LS-Dyna model in ICFD, but I have extremely high drag and lift forces, which are 1000 times higher than results from other CFD solvers and published literature. The model set up (boundary conditions, turbulence model, boundary layer set up) are almost the same. <br><br>From *ICFD_DATABASE_DRAG, pressure and viscous forces are obtained, and from both .dat generated, I can see that 95% of the force comes from the pressure terms. I have also plotted the drag distribution and the force contribution of each element, and what stands out is that 200N\/element are constantly produced independly of velocity, from 2m\/s until 50m\/s. I have attached the force per element plot in the first image below and the drag distribution in the second image (I still don’t completely understand this latter plot).<br><br>Does anybody have any clue why these strong forces appear and keep almost constant from low velocities?<br><br>Thank you very much,<br>Arnau<\/p><p><\/p><p><\/p><\/p>\n","protected":false},"template":"","class_list":["post-382404","topic","type-topic","status-answered","hentry","topic-tag-drag","topic-tag-drag-force","topic-tag-icfd-1"],"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\n\t\t\n\t\t\n\t\t