Flow over an airfoil
AIM -
Perform a flow simulation in SOLIDWORK over an Airfoil.
OBJECTIVES -
To make a 3D model of NACA0017 Airfoil.
To perform a flow slimulation over NACA0017 Airfoil at different angle of attack.
Comparsion between lift and drag force.
INTRODUCTION -
Flow simulation is a form of computational fluid dynamics which digitally replicates flows in surface water or collection systems. Performing flow simulation allows for the prediction and analysis of how a flow might be impacted by complex geometry in an operational environment.Flow simulation is not limited to liquids and may be applied to gases as well. Flow simulation is especially useful in trenchless applications to predict how a system will behave in low and high use situations, such as dry vs. storm weather simulations for drainage systems.Flow simulation can be used to identify and develop solutions and methods, as well as predict the effect of changes to a system. At times, however, the observed flow may differ from simulated flows. In these cases the estimated flow simulation needs to be updated with measured data.
Airfoil - An airfoil or aerofoil is the cross-sectional shape of a wing, blade (of a propeller, rotor, or turbine), or sail (as seen in cross-section).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. subsonic flights, airfoils have a characteristic shape with a rounded leading edge, followed by a sharp training edge, often with a symmetric curvature of upper and lower surfaces. Foils of similar function designed with water as the working fluid are called hydrofoils.The lift on an airfoil is primarily the result of its angle of attack. When oriented at a suitable angle, the airfoil deflects the oncoming air (for fixed-wing aircraft, a downward force), resulting in a force on the airfoil in the direction opposite to the deflection. This force is known as aerodynamic force and can be resolved into two components: lift and drag.
CASE SETUP -
Initially we have build a model of airfoil with the help of naca0017 airfoil data file. The data file bascially contains the values which helps us to build a airfoil.
Now, since the airfoil was modelled by the help of naca0017 data file. But still we need to tilt the airfoil at 2 degree , 4 degree , 6 degree , 8 degree , 10 degree. We have achieved these model at each of these degrees.
Steps for creating the model at angle of attack -
Once we have modelled the airfoil through the data we need to create a new sketch.
Build the same model through convert entites and add a length at end of airfoil which completely closes the model.
Next , rotate the airfoil at desired angle of attack. In our case it is 2 degree , 4 degree , 6 degree , 8 degree , 10 degree .
At last exit the sketch and extrude the model at favourable length.
NACA0017 AIRFOIL MODEL -
Above is the airfoil model with the tilt angle of 2 degree. Here if we see the blue color airfoil is the naca0017 data generated sketch.
SIMULATION SETUP -
After is model is created save it and move to flow simulation .
So, the fluid flow is generally air and the velocity must be set high . In this case it must be around 600m/s but for these case i have taken less velocity (due laptop configuration compatiability). So, generally the computational domain must be greater at the exit side than at the opening side. This is done generally to evaluate the flow smoothness or we can say how the nature of fluid behaves once it passes the aerofoil. The basic global mesh was generated with the grid size of 3 but we have also added inert mesh at the top curve of airfoil. After the solver was finished we had set the velocity and pressure cutplot along with surface goal forces i.e., X and Y. Basically the surface goal force at Y axis is lift force and surface goal force at X axis is drag force.
Will we look at the velocity and pressure plot at each angle of attack.
CASE 1 - Velocity and Pressure plot at Angle of attack 0 degree.
Velocity plot -
Here, I have taken the velocity of 5 m/s which is totally no considerable but totally learned the concept and its behaviour over the airfoil. So, the velocity plot shows us that at the peak entry point of airfoil the velocity is the same as given input but gradually decrease as the flow continues .
Pressure plot -
The pressure here quite seems to be moderate at the peak tip point . Where we the movement it goes decreasing.
Surface Forces along X & Y axis -
Above we can see the forces value generated at the surface along the X and Y axis .
CASE 2 - Velocity and Pressure plot at Angle of attack 2 degree.
Velocity plot -
Pressure plot -
Surface Forces along X & Y axis -
CASE 3 - Velocity and Pressure plot at Angle of attack 4 degree.
Velocity plot -
Here, I have taken the velocity of 60 m/s just to see any changes can be noticed but still it is totally no considerable but totally learned the concept and its behaviour over the airfoil. So, the velocity plot shows us that at the peak entry point of airfoil the velocity is the same as given input but gradually decrease as the flow continues .
Pressure plot -
Surface Forces along X & Y axis -
CASE 4 - Velocity and Pressure plot at Angle of attack 6 degree.
Velocity plot -
Here, I have taken the velocity of 30 m/s just to see any changes can be noticed but still it is totally no considerable but totally learned the concept and its behaviour over the airfoil. So, the velocity plot shows us that at the peak entry point of airfoil the velocity is the same as given input but gradually decrease as the flow continues .
Pressure plot -
Surface Forces along X & Y axis -
CASE 5 - Velocity and Pressure plot at Angle of attack 8 degree.
Velocity plot -
Here, I have taken the velocity of 60 m/s just to see any changes can be noticed but still it is totally no considerable but totally learned the concept and its behaviour over the airfoil. So, the velocity plot shows us that at the peak entry point of airfoil the velocity is the same as given input but gradually decrease as the flow continues .
Pressure plot -
Surface forces along X and Y axis -
CASE 6 - Velocity and Pressure plot at Angle of attack 10 degree.
Velocity plot -
Pressure plot -
Surface forces along X and Y axis -
CONCLUSION -
from the above study we can conclude that with increase of lift force the drag force also increases. At 0 degree of attack basically the lift force is zero due to the position of airfoil. Always consider the velocity value greater to get the optimum results.