Flow over an airfoil
Aim - To analyse flow over an aerofoil using solidworks.
Introduction:
CFD analysis of flow over aerofoil is carried out and drag forces and lift forces are calculated at various angle of attacks.NACA0018 aero foil is selected for analysis perpose.
angle of attack is varied from 0 to 10 deg at interrval of 2 deg.
Procedure:
1)naca0018 aero foil data is imported to excel.then data is formatted with format suitable for solidworks and saved in txt extension.
2)using insert curve feature text file is imported.
3)curve is copied into another sketch. make sure it is closed.
4)using rotate entities option angle of attack is specified.
5)flow simulation wizard is used to set up air flow speed. ,medium etc.
6)computational domain is selected at 2d in XY plane.make sure it is large enough to capture field.
7)mesh is adjusted to finer and local mesh generation is done on surface of aerofoil.
8)global goal is set as force along x and y axes.and surface goal is set as forces on surface of aerofoil in x and y direction.
9)now run the simulation.
10)insert pressure contour and goal plot to observe drag force and lift force and run simulation until they become stagnant.
11)now stop simulation and insert veloocity contour.
12)see the results.
geometry and meshing -
boundary conditions -
flow velocity -600 m/s ,NTP condtions.
Results -
1)case-1, aoa =0 deg.
simulation-
velocity contour-
drag force graph -
lift force graph -
drag force and lift force -
2)case-2 ,aoa -2 deg
simulation-
velocity contour-
drag force graph-
lift force graph-
drag force and lift force-
3)case-3, aoa-4 deg
simulation-
velocity contour-
drag force graph-
lift force graph-
drag force and lift force-
3)case-4, aoa-6 deg
simulation-
velocity contour -
drag force graph-
lift force graph -
drag force and lift force -
5)case 5- aoc- 8 deg
simulation-
velocity contour -
drag force graph -
lift force graph -
drag force and lift force -
6)case-6 ,aoa -10 deg
simulation -
velocity contour -
drag force graph -
lift force graph -
drag force and lift force -
variation of drag force and lift force for given angke of attacks-
conclusion -
from above it can be concluded that for given angle of attack range lift force is dirctly prortional to angle of attack and drag force increases slightly with increase in angle of attack for NACA0018 aerofoil.