4.4 ANSYS REPORT:
A numerical study on the 3-D aerofoil of a double rear wing of formula1 car has been carried out in ANSYS FLOTRAN CFD analysis package. ANSYS analysis has been done for inlet velocity of about 51.11meter per second with k-e turbulent model. Preprocessing stage: A 3-D rear wing of formula 1 car has been created in the solid works modeling tool as obtained from the Design-Foil software. This rear wing section has been enclosed in the cubical volume representing the wind tunnel. The 3-D model is free meshed with triangular elements up to 3, 36,847elements. Processing stage: The boundary conditions and the fluid properties are applied as mentioned in the table above. Post processing: the results obtained can be shown by the various plots like Velocity vector, pressure contour plots. Animation of particle flow at required points are recorded.
PREPROCESSING STAGE (GEOMETRY AND MESH GENERATION):
Fig 4.3: Geometric creation
Fig 4.4: 3D volume
Fig 4.5: CDG Rear wing model subtracted from the wind tunnel
Fig 4.6: Mesh Generation (model)
Fig 4.7: Fine meshing near the downstream
Processing: stage: Applying Boundary conditions
Fig4.8: Boundry conditions
Fig4.9: Boundary condition for a 3D model
Fig 4.10:section through which the flow over the 3D rear wing is analyzed [pic]
Fig4.11 guide for changing the workplane
The figure 4.3 depicts the geometry creation where wind tunnel is created in the ansys accommodating the 3D rear wing model which is scaled through the half a section. The 3D rear wing model is subtracted from the main wind tunnel by using the Boolean subtraction operation.The figure 4.4 shows the entire 3D volume which actually consists of two volumes one related to the rear wing element and other related to the wind tunnel.The figure 4.5 shows the Rear wing model being subtracted from the wind tunnel.The figure 4.6, 4.7 deals with the mesh generation for the entire geometry where the wind tunnel is coarse meshed and the rear wing model and the downstream is fine meshed to the lowest order in order the predict the clear flow separation over the aero foils.The figure 4.8, 4.9 shows the boundary condition being applied over the entire geometry(as explained in the table 4.1). The figure 4.10, 4.11 depicts the section through which the flow over the 3D rear wing is analyzed.This can be done by the changing the working plane to the region that we haveanalyzed and then changing the type of the plot and the giving the region for the cutting plane. POST PROCESSING:
For the inlet velocity of 51.11meter per second
1) VELOCITY VECTORS PLOT
Fig 4.12: Velocity vector plot
Fig 4.13: vector plot zoomed over the rear wing
Fig 4.14: velocity plot over the upper wing
Fig 4.15: velocity plot over the lower wing
Fig: 4.16: recirculation zone in the velocity plots
• From the above plots it has been observed that the entire wing section is in the low pressure area and the highest velocity has been observed above the geometry. Flow separation has been observed at the leading edge of the aerofoils.
• The velocity profile has been clearly developed with minimum being at the surface and gradual increase to the maximum velocity above the rear end of the geometry .
• This clearly explains the formation of the two separate regions over the aerofoil surface, high pressure region around the upper surface of the aerofoil and the lower pressure region around below the aerofoil surface.
• Due to this difference in the pressures on the surface of the aerofoil there is greater aerodynamic load on the aerofoils which helps in reducing the horizontal component of the total force and there by reucing the drag and increasing the vertical component of the total force in the opposite direction viz,downforce,thus helping in pushing the vehicle to the ground.
• Shedding and...
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