I think you should use k-omega SST, rather than k-epsilon, as k-epsilon is not very accurate in adverse pressure gradients, so not viable for aerofoils. It might not show a problem here, but at higher angle of attack it will not simulate the flow correctly, as it does not show flow separation. You could also see that you lift and drag coefficients were really wrong, they usually have values around 0-2 for Cl and like 0.015 or so for Cd, definitely not 6000. You should also do mesh refinements rather than making the whole area really fine mesh.
Thank you for this! This will help me with my third year project on studying suction and blowing flow control on an aerofoil and how it affects aerodynamics :)
Why would the fluid flow be normal to boundary? Should it not have an X component instead, as being normal to boundary will disrupt a free-flow condition?
You will likely have to zoom in on the trailing edge and connect the two points at the very end with a short line. This should fix your continuity issues
good video, i am having some doubts . for this case i want to write a coefficient of moment also for the different angle of attack. what are the moments points and moment axis i should consider. and for also 3d cases similar like this one i wanna know about the co eff- moment . kindly explain me .
Brother the coordinates imported always have the tail area open (upper region not joined with the lower one) so I can’t generate surface from edges as can’t get edges joints generated.
I’ve had that happen to me a few times as well. The gaps have been very narrow in my experience so I’ll usually make a line to connect the two rail points and complete the surface. Since the gap is narrow, the line rarely hurts the simulation (it’s actually more accurate to manufactured wings since they almost always have a thin flat end at the back of the airfoil). If you need a very fine tip, you can also alter the coordinate for one of the tips so that they join together. Hope one of those works!
If you're in setup go to Results -> Create (under Surface) -> Zone -> surface-body (on left) -> create it will show up. I had trouble getting it to work too.
In sketch mode you should be able to zoom in on the trailing edge corner (where the point is missing) and draw a line to connect the two points that are present. Once you do this, you will be able to crate a line from the sketch, then a surface from that line and the line created from the coordinate file.
Hey, After I have given Initialize in the hybrid initialization, it says "WARNING: unassigned interface zone detected for contact_region-trg" and Unassigned interface zones found. Flow is not initialized. Any help would be much appreciated. Really need it.
Good video about CFD, but your explanation about the lower pressuere on the top of the airfoil (19:40) is wrong, the igual transit time "theory" is wrong because don't exist any type of physical principle that implie that the air on the top must reach the end of the airfoil at the same time that the air on the bottom, in fact if you analyses a wind tunel experiment you will see that the air on the top reach the end of the airfoil before the air on the bottom what proof that your explanaton is wrong. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-UqBmdZ-BNig.htmlsi=ZWkgGfPqWnOamMJH Here is a video of a wind tunel.
How can you feed people with this s***t being so confident? An impressive skill. 6000 Cd? For real?! List of critical mistakes: -shitty mesh without inflation layer around the foil; -wrong turbulence model absolluetly; -no reference values have been set for propper coefficient calculation. My suggestion, delete this, fix mistakes, upload again. It is an anti tutorial, harmful one.
