3-D wing analysis problem
Hi guys!
Facing a problem while doing the analysis of a 3D wing (finite). The geometry has been meshed in gambit. I have used a structured boundary layer.. and the remaining mesh too is structured. Used the cooper scheme to get from 2D to 3D. The fineness of the boundary layer had to be reduced because some of the elements were getting a negative volume or were getting too skewed. Eventually, got the right mesh (according to the mesh check of Fluent). But on running analysis, got some really wrong results.. The conditions: 1. Laminar 2. velocity inlet at 15m/s 3. air, incompressible- constant density 4. outlet boundary layer - "outflow" And the results that I got were quite alarming. All the pressure contours on the wing were pointing downwards!! 1. What could be the reason for this? 2. Could I use better boundary conditions? Thanks! |
velocity inlet in fluent
Dear friends,
In fluent, For analysis of 2D naca0012 airfoil velocity inlet we give vcostheta in x component & vsintheta in y component, v is inlet velocity. 1)here i start analysis of 3D wing, for that i take naca 0012 airfoil chord '1'& extrude 100mm, in gambit and analysis in fluent i have doubt how to set velocity inlet, here i consider my velocity is 3m/s, then what is xyz component in inlet velocity boundary condition,please let me know. 2)if you consider 3D wing, (vtantheta for z component) is correct or wrong, please let me know. 2) how to find angle of attack for 3D wing? please let me know |
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velocity inlet in fluent
Dear cfd seeker,
thanks for your kind response, In fluent, For analysis of 2D naca0012 airfoil velocity inlet(boundary condition) we give vcostheta in x component & vsintheta in y component. if u consider 3D wing what is z component,(velocity inlet ie boundary condition) i think vtantheta for z component? it is correct or wrong please let me know |
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velocity inlet in fluent
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Dear cfd seeker,
thanks for information, i know the definition of angle of attack, i already did 2D analysis of naca 0012, but 3D wing i dont know how to give boundary condition in fluent especially velocity inlet, in my case velocity is 10m/s. For 3D wing,here i attached three image, which is suitable for my case if v=10m/s, please see my attached image, let me know. |
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x-component= 10*cos(AOA) y-component=10*sin(AOA) Z=0 AOA= angle of attack there is no difference in boundary conditions for 2d and 3d cases |
velocity inlet in fluent
Dear cfd seeker,
thanks, for your help, then which image i have to select and give velocity inlet,let me know. |
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velocity inlet in fluent
Dear cfd seeker,
thanks for your help. |
velocity inlet in boundary condition
Dear cfd seeker,
i am doing steady analysis in for my 3D wing, for that i mesh in gambit & import in fluent. i consider solver is pressure based &my model is laminar flow, Know value i have is velocity= 5m/s, area=0.0102 m2, length=0.065m. [boundary condition-velocity inlet, pressure outlet, remaining faces are symmetry& wing is wall] In fluent i dont how to set velocity inlet, for v=5m/s, i dont which velocity specification method is i have to selected under dropdown? please help me i get confused while read the fluent user guide |
uneven flow at aoa
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but whet i set inlet velocity at positive angle of attack i get the flow accumulated at upper surface of wind tunnel giving uneven flow throughout the wind tunnel ( higher velocity at upper surface of wind tunnel and lower velocity at lower surface of wind tunnel) and i have chosen boundary conditions as symmetry for both upper and lower surface of wind tunnel(air domain around wing is rectangular box) |
Greetings bikalpa10
i didn't understand your problem what is your domain size? |
thanks kumar
but actually i figured out where i was going wrong i choose boundary condition for wind tunnel wall as velocity inlet and that worked out for me. thanks anyways |
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