hi every one
I am having an issue in calculating sum forces which i applied on a conical surface.
I have CFD data in X,Y, Z & pressure Format which i got from cfd software. this text file i am reading it in field table and applying the pressure on to the conical surface. the coordinates and the contour are matching to the CFD result.
but when i am checking the mechanical load summary they are not matching to the CFD resultant force .
i.e the CFD resultant forrce is like Fx = 1000N Fy =1000n and Fz = 2000N
but in Nx the resultants force is Like Fx = 17000N fy = 1000n Fz = 2000N
X axis is along the length of cone y axis Vertical and Z axis lateral
plz clarify why the Fx force is not matching
Note: all the pressures are applied normal to the surface.
Try to show some steps how you apply the loads to the model and paste some screenshots, it will be easier to help. Which methode you use for application of laod?
I would also check the coordinate systems, with respecto to which you are checking the Mechanical Load Summary. Export of Lift and Drag is usually given in local coordinate system, and Mechanical Load Summary is by default given in Native CSYS.
Thank you for your reply
the Procedure i followed is
1. Imported the geometry as a surface model and meshed.
2. creating a coordinate system which will match the CFD data
( the High lighted one)
3. getting the CFD data in to the field
4. checking the pressure cloud before interpolation
5. applying pressure load
6. cross verifying the interpolated data by extracting the contour
7. Checking the mechanical load summary
these are the steps i fallowed
plz clarify the error
Can you clarify how you read forces / pressures from CFD ? Maybe you read also 'rear' surface of the cone that is not shown here (?).
Another thing that may influence accuracy of readings is the difference between the meshes sizes, however such difference is too big.
What you can check also: units of output / import and interpolation methodes, but first check how you read forces from CFD model.
the force is calculated by
1.The total force component along the specified force vector is computed by summing the dot product of the pressure and viscous forces on each face with the specified force vector
Fa = a.Fp + a.Fv
Fa = total force component
a = specified force vector
Fp = pressure force vector
Fv = viscous force vector
2. there is no rear surface both in CFD and in FEM so i did not considered them
3. I am exporting in SI units and same has been used while Importing
4 I have played with all the interpolation methods but the load summary is not changing
The cfd analysis was done in FLUENT software and the data was given to me to do the structural analysis, i have verified the process they followed.
note: same thing i have checked with FEMAP also the result is same
If you have obtained the same results from the same data using 2 different post processing tools, that suggests that the values extracted from the supplied data are correct and that maybe you should re-examine the process of obtaining the data from the source to ensure it really represents what you think it represents.