Lift and Drag Analysis of NACA 1412 Airfoil Using Unstructured Mesh

Abstract

This research paper gives insight to the analysis of NACA 1412 airfoil. The airfoil is the two-dimensional cross section of the aircraft’s wing. The aircraft flies due to generation of the lift, this lift is caused by the pressure difference on the upper and lower surface of the airfoil. The pressure on the lower surface is greater than the pressure on upper surface which provides a lift to the airfoil. We are going to see the airfoil’s behaviour in incompressible flow at different angles of attack with constant velocity. In this research, we are going to use the Ansys software to do the analysis. This research is based on the computational fluid dynamics concepts. At the end, we will see how the lift and drag changes at different angles of attack and some graphical results from the research.

Introduction

I. INTRODUCTION

When the aircraft is flying, there are four main forces which acts on it, they are, lift, drag, thrust and gravity. Wherever there’s a lift, drag is there. To reduce this drag force and to increase the aircraft’s efficiency the designers use different types of airfoils like symmetrical and unsymmetrical or camber. Before all the software, we had to do all the analysis in the wind tunnels, but now Ansys has taken its position and it’s playing an important role in the aviation industry. Here, we are going to use the Design Modeler to design the airfoil and the respective domain and grid our geometry in the Mesh. Fluent solver makes the important part of the analysis. NACA 1412 is a four-digit airfoil. It is an unsymmetrical or cambered airfoil. National Advisory Committee for Aeronautics first developed these NACA airfoils. In the four digits, the first number denotes the maximum camber in percentage with respect to the chord. Second number indicates the location of the maximum camber which is given in tenth of chord and the percentage of  maximum thickness of the airfoil is given by the last two numbers with respect to chord. In NACA 1412, we have camber of 1% which is located at the 40% behind the leading edge of the airfoil and it has maximum thickness of 12%. This paper describes the behaviour of the airfoil at 0, 3, 6, 9 and 12 degrees of angle of attack at the constant velocity and then the values of coefficient of lift  and coefficient of drag will be plotted with the help of graphs.

II. BASIC TERMINOLOGIES OF THE AIRFOIL

Lift : The aerodynamic force which is perpendicular to the direction of the wind due the pressure difference between upper and lower surface of the object is called lift.

Drag : It is an opposing force acting on a body.

Angle of attack : The angle between the chord line and free stream velocity is called angle of attack.

Chord line : The straight line joining the leading edge and trailing edge is called chord line.

Mean camber line : The line dividing the airfoil into two equal parts is known as mean camber line.

Reynold’s number : It is the ratio of inertial force to the viscous force.

Conclusion

As the angle of attack increases, the Cl and Cd values increases. From the figures 5, 6, 7, 8 and 9, it can be seen that the upper surface of the airfoil experiences low pressure and the lower surface experiences high pressure. In case of velocity, the velocity is higher over the airfoil as compared to the bottom of the airfoil. At certain angle the lift suddenly goes down due to the gradually increasing drag and the flow separation. This condition is called stalling and the angle is known as critical angle. This type of airfoil is used in the aircraft’s wing.

References

[1] John D. Anderson, Fundamentals of Aerodynamics, sixth edition, Mc Graw Hill Education [2] Vani Sadadiwala “A Detailed Study: CFD Analysis of NACA 0012 at Varying Angles of Attack”, International Journal for Research in Applied Science & Engineering Technology (IJRASET), Volume 9 Issue VII, July 2021 [3] Anagha S Gowda “Comparison of Aerodynamic Performance of NACA 4412 and 2412 using Computational Approach”, International Journal of Engineering Trends and Technology (IJETT), Volume 67 Issue 4, April 2019 [4] H K Versteeg and W Malalasekera, “An Introduction to Computational Fluid Dynamics”, second edition, Pearson Education [5] S. Kandwal, Dr. S. Singh “Computational Fluid Dynamics Study Of Fluid Flow And Aerodynamic Forces On An Airfoil”, International Journal of Engineering Research & Technology (IJERT), Volume 1 Issue 7, September 2012 [6] R. K. Rajput, Fluid Mechanics and Hydraulic Machines, fifth edition, S. Chand and Company Ltd. [7] Ira H. Abbott and Albert E. von Doenhoff, Theory of Wing Sections Including a Summary of Airfoil Data, Dover Publications Inc. New York [8] Airfoiltools. [Online]. Available: http://airfoiltools.com/

Copyright

Copyright © 2023 Sanket Thorwat. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.