Flow over an airfoil
AIM:
In this project, we have to perform CFD analysis of 2D-subsonic flow over the NACA airfoil-0017 for the various angles of attack are taken and the drag force and the lift force are calculated.the airfoil is created using SOLIDWORKS and CFD analysis is carried out using Flow Simulation Wizard at various angles of attack from 0° to 10° with an interval of 2°. Velocity distributions over NACA-0017 airfoil for different angles of attack are presented.
INTRODUCTION:
Airfoil is defined as the cross-section of a body that is placed in an airstream in order to generate useful aerodynamic force.
Computational Fluid Dynamics (CFD) has fascinated researchers, as it is a fast, accurate, and reliable method of analyzing the variation of hydrodynamic properties of the flow over and within a body. Computational Fluid Dynamics (CFD) is a branch of fluid mechanics that uses numerical methods and algorithms to solve complex problems involving fluid flow.
Effect of angle of attack:
Increases as the angle of attack increase the lift force increase proportionately. And a certain point, called critical angle of attack, upper surface flow is more separated and the airfoil or wing is producing its maximum coefficient of lift.
GEOMETRY:
SKETCH (from data points ):
EXTRUDED PART:
BOUNDARY CONDITIONS:
|
INPUTS |
VALUES |
|
Analysis type |
External flow |
|
units |
Si units |
|
Time dependant |
Total analysis time:5 sec |
|
Output time:1 sec |
|
|
Fluid |
Air |
|
Density |
1.225 kg/m^3 |
|
Chord length |
1 m |
|
Inlet velocity |
600 m/s |
PROCEDURE:
In this we have taken the airfoil co-ordinates given as per the standards and then sketch that by using the command insert =>curves
the sketch is then extruded to the value of .40m and then the flow simulation analysis is done. for various angles, the sketch was rotated for the given value by using rotate entities.
RESULTS:
Results are taken for the various angle of attacks.
force along the x-axis is Drag force.
force along the y-axis is Lift force.
Case 1:0°- Angle of attack:
velocity -contour plot
drag force and lift force -table
Graph
Drag force: Lift force:
Case 2: 2°- Angle of attack:
Velocity-contour plot
drag force and lift force -table
Graph
Drag force: Lift force:
Case 3: 4°- Angle of attack:
Velocity-contour plot:
drag force and lift force -table
Graph
Drag force: Lift force
Case 4: 6°- Angle of attack:
Velocity-contour plot:
drag force and lift force -table
Graph
Drag force: Lift force:
Case 5: 8°- Angle of attack:
Velocity-contour plot:
drag force and lift force -table
Graph
Drag force: Lift force:
Case 6: 10°- Angle of attack:
Velocity-contour plot:
drag force and lift force -table
Graph
Drag force: Lift force:
COMPARISON STUDY -DRAG AND LIFT FORCE:
| Angle | Drag force | Lift force |
| 0 | 612.913 | 0.964 |
| 2 | 673.191 | 1669.886 |
| 4 | 831.028 | 3293.568 |
| 6 | 1108.459 | 4890.182 |
| 8 | 1515.083 | 6502.11 |
| 10 | 1998.225 | 8081.566 |
GRAPH:
DRAG FORCE:
LIFT FORCE:
COMPARISON PLOT FOR DRAG AND LIFT FORCE:
CONCLUSION:
- The simulation of NACA-0017 airfoil was performed and the drag and lift force plots are taken.
- The drag force initially increased gradually and then finally quadratic line (plot)was obtained as the angle increases.
- The lift force was obtained as a linear curve(no deviations) for the various angle of attack.
- from the above plots, for various angles, the drag and lift force plot values are compared.
- it is also noted that the constant value for drag and lift force was achieved in earlier iterations as the angle of attack increases
- For airfoil, the drag is nearly constant at small angles (+/- 5 degrees). As the angle increases above 5 degrees, the drag quickly rises because of increased frontal are and increased boundary layer thickness.