FLOW SIMULATION OVER AN AIRFOIL IN SOLIDWORKS
AIM: TO SIMULATE FLOW OVER A NACA 0017 AIRFOIL WITH VARYING ANGLE OF ATTACKS USING SOLIDWORKS
INTRODUCTION: An airfoil or aerofoil is the cross-sectional shape of a wing, blade (of a propeller, rotor, or turbine), or sail. An airfoil-shaped body moving through a fluid produces an aerodynamic force. The component of this force perpendicular to the direction of motion is called lift. The component parallel to the direction of motion is called drag.
GOVERNING EQUATIONS:
- LIFT FORCE –
`L=C_l×(ρ×V^2)/2×A`
- DRAG FORCE –
`D=C_d×(ρ×V^2)/2×A`
where,
`C_l=`Coefficient of Lift
`C_d=`Coefficient of Drag
`ρ=`Density of Fluid (air)
`V=`Velocity of Fluid (air)
`A=`Frontal Area / Winf Area /Cross sectional Area
GIVEN: Link to the Sample Airfoil Data –
https://drive.google.com/file/d/12ZIqEQ5SuVYwODgf_EIo3Q8A_N1a8mcP/view
PROCEDURE:
- Initially, the Airfoil Sample Data file is used to draw the airfoil spline followed by the closing of the geometry. It is extruded to a certain extent for satisfactory results. The geometry can be rotated for varying Angle of Attacks.
- Flow Simulation is set up and a Transient Simulation solver is used with a specified velocity of 600m/s along x-axis. A 2D Computational Domain is assigned with adequate width and height.
- Surface Goals comprising of Forces in x-direction (Drag Force) and y-direction (Lift Force) are mentioned and a Mesh is defined with a separate Local Mesh for fluid cells in the periphery of the surface boundaries.
- The Simulation is executed and is carried out until the solution converges. A Velocity Cut Plot is proposed and Goal Plots are built for Drag and Lift Forces.
RESULTS:
- Angle of Attack = 0 deg
VELOCITY CONTOUR
| Goal Name | Unit | Value | Averaged Value | Minimum Value | Maximum Value | Progress [%] | Use In Convergence | Delta | Criteria |
| SG Force (X) 1 | [N] | 0.00056272 | 0.000562811 | 0.0005626 | 0.000563067 | 100 | Yes | 4.66815E-07 | 0.000102189 |
| SG Force (Y) 1 | [N] | -8.68775E-06 | -9.30451E-06 | -9.74571E-06 | -8.68247E-06 | 100 | Yes | 1.16835E-07 | 3.5875E-07 |
DRAG FORCE
The drag froce reduces drastically after the fluid makes an initial contact with leading edge of the airfoil and then becomes constant.
LIFT FORCE
The lift force is subsequently higher during the emergence of the flow and shows sharp ascent and descent over the entire flow simulation.
- Angle of Attack = 2 deg
VELOCITY CONTOUR
| Goal Name | Unit | Value | Averaged Value | Minimum Value | Maximum Value | Progress [%] | Use In Convergence | Delta | Criteria |
| SG Force (X) 1 | [N] | 0.000592894 | 0.000593639 | 0.000592894 | 0.000594731 | 100 | Yes | 1.59574E-06 | 9.44707E-05 |
| SG Force (Y) 1 | [N] | 0.000988178 | 0.000988121 | 0.000986287 | 0.000990401 | 100 | Yes | 2.27179E-06 | 1.01852E-05 |
DRAG FORCE
It follows a similar trend to the 0 degrees angle of attack case.
LIFT FORCE
The Lift Force offers an exponential trend. An extremely high value is obtained in the starting but constants out over the passage of time.
- Angle of Attack = 4 deg
VELOCITY CONTOUR
| Goal Name | Unit | Value | Averaged Value | Minimum Value | Maximum Value | Progress [%] | Use In Convergence | Delta | Criteria |
| SG Force (X) 1 | [N] | 0.000695777 | 0.00069579 | 0.00069545 | 0.00069621 | 100 | Yes | 5.38944E-07 | 7.19416E-05 |
| SG Force (Y) 1 | [N] | 0.001975623 | 0.001975238 | 0.001973993 | 0.001976488 | 100 | Yes | 8.03657E-07 | 2.28869E-05 |
DRAG FORCE
It follows a similar trend to the 0 degrees angle of attack case.
LIFT FORCE
The Lift Force follows a similar trend to that of 2 degrees angle of attack case.
- Angle of Attack = 6 deg
VELOCITY CONTOUR
| Goal Name | Unit | Value | Averaged Value | Minimum Value | Maximum Value | Progress [%] | Use In Convergence | Delta | Criteria |
| SG Force (X) 1 | [N] | 0.000867562 | 0.00086744 | 0.000866387 | 0.000868299 | 100 | Yes | 5.59592E-07 | 4.90612E-05 |
| SG Force (Y) 1 | [N] | 0.00294654 | 0.002946837 | 0.002945721 | 0.002947693 | 100 | Yes | 6.0129E-07 | 3.91057E-05 |
DRAG FORCE
A sudden bend is observed at the neck of the plot depicting the approach of Angle of Stall.
LIFT FORCE
The plot smoothens out after the exponential increase depicting the smooth flow over and below the airfoil.
- Angle of Attack = 8 deg
VELOCITY CONTOUR
| Goal Name | Unit | Value | Averaged Value | Minimum Value | Maximum Value | Progress [%] | Use In Convergence | Delta | Criteria |
| SG Force (X) 1 | [N] | 0.001121612 | 0.001121971 | 0.001120921 | 0.001123027 | 100 | Yes | 1.44219E-06 | 2.89201E-05 |
| SG Force (Y) 1 | [N] | 0.003943022 | 0.003944284 | 0.003941623 | 0.003945857 | 100 | Yes | 1.93917E-06 | 5.68908E-05 |
DRAG FORCE
The bend near the neck extensifies and shows greater chances of stall situation.
LIFT FORCE
The plot follows similar trend to that of the 6 degrees angle of attack case.
- Angle of Attack = 10 deg
VELOCITY CONTOUR
| Goal Name | Unit | Value | Averaged Value | Minimum Value | Maximum Value | Progress [%] | Use In Convergence | Delta | Criteria |
| SG Force (X) 1 | [N] | 0.001424517 | 0.001424784 | 0.001422855 | 0.001426073 | 100 | Yes | 1.46946E-06 | 1.9067E-05 |
| SG Force (Y) 1 | [N] | 0.004916533 | 0.004917477 | 0.004914945 | 0.004919298 | 100 | Yes | 2.89486E-06 | 7.88827E-05 |
DRAG FORCE
A suuden distortion is observed initially indicating the increase in the frontal area, i.e. the area that comes in contact with the fluid (air). The probability of stall increases.
LIFT FORCE
The plot signifies smoother transition of flow over the airfoil but a sudden dip near the neck region may counter the required motion of flow.
CONCLUSION: The Flow over an airfoil gives a clear perspective of the lift force that gradually outshines the drag force in order to make the airplanes and other objects fly. The balance between these two forces yields the required motion and height that we desire.