1. Introduction
Aerodynamic Performance Analysis of A Non Planar C Wing using Experimental and Numerical Tools
Mano Prakash R., Manoj Kumar B., Lakshmi Narayanan
Applied Aerodynamics Conference Modelling & Simulation In The Aerodynamic Design Process
BRISTOL / JULY 2012

2. Outline Introduction Computational Fluid Dynamics Wind tunnel Testing1
Introduction 2
Computational Fluid Dynamics 3
Wind tunnel Testing 4
Induced drag comparison 5
Radio – Controlled model 6
Conclusions and Recommendations

3. Outline 1
Introduction

4. Thrust required curve for jet aircraft
Introduction
Accounts for 80% – 90% of the aircraft’s climb drag.
Possible ways of reduction:
Increased span (Weight!)
Non planar concepts -
Winglets, C wing, etc.
Thrust required curve for jet aircraft

5. Introduction
Objective
To perform force (lift and drag) measurements on a C-wing with a NACA 0012 profile at different angles of attack and compare the results obtained to those corresponding to a conventional plane rectangular wing.
To incorporate a C-wing into a remote controlled aircraft that can be maneuvered using the ailerons mounted on the C-wing.

6. Methodology
To carry out CFD analyses on C wing geometries to finalize the wind tunnel model based on optimum lift/drag ratio.
Front view
Right side view

7. Outline 2
Computational Fluid Dynamics

8. CFD 3D Inviscid flow simulation Tools employed:
CATIA V5 is used for 3D models.
Grid generation for the models is carried out using ANSYS Workbench.
Flow computations are performed using ANSYS CFX.
Postprocessing is carried out using CFD Post.

9. Initial Geometry Model 1
Selection Criteria: Reference wing dimensions -
Span = 500mm, Chord = 150mm, Aspect Ratio = 3.33

10. Surface grids
Coarse
Medium
Fine
Elements:

11. Grids -Cut Section at 50% of span
Coarse
Medium
Fine
Growth
rate

12. Flow Field Conditions
Reynolds Re = 3 × based on chord, c = 0.13m and Number flow velocity, V∞ = 35m/s
Mach number, M∞ = 0.1
Turbulence model = Laminar
Inlet = Velocity, V∞ = 35m/s
Outlet = Pressure, P = 0atm
Walls = Free slip wall

13. CFD Results Force convergence M∞ = 0.1, Re∞ = 3 × 105, α = 5o
Force coefficients do not asymptote on fine grid.

14. Final model
Lift / Drag Vs. Angle of attack
𝐿 𝐷 α

15. Outline 3
Wind tunnel Testing

16. Wind tunnel Subsonic wind tunnel
Hindustan College Of Engineering, Anna University, Chennai, India.
Tunnel type : Open loop tunnel
Test section :
60cm × 60cm × 200cm Velocity range: 0 – 80m/s

17. Experimental set up Model Material used: Fiberglass
Total pressure taps: 32
Manufacturing accuracy: ± mm

18. Results
𝐿 𝐷
𝐿 𝐷 α α

19. Outline 4
Induced drag comparison

20. Planar wing

21. C-wing

22. Interference factor b1 = 435mm b2 = 140mm h = 85mm b2/b1 = 0.32
h/b1 = 0.2
σ = 0.197
σ* = 0.98

23. Comparison curve
𝑪𝑫𝑰 α

24. Outline 5
Radio – Controlled model

25. Model Materials: Fuselage - Spad board reinforced with balsa wood.
Wing and tail plane - Coroplast reinforced with balsa wood.
Controls: Speed, aileron, elevator and rudder

26. Outline 6
Conclusions and Recommendations

27. Conclusion and Recommendations
Conclusions
High L/D ratio is achievable.
Significant reduction in induced drag.
Height (vertical separation) and span ratio has a direct influence on the overall efficiency.
Recommendations
Appropriate airfoil should be selected.
Design optimization should be coupled with CFD studies.
CFD studies should include viscous effects.
Coupled aerodynamics, stability and structural analyses should be conducted.

28. THANK YOU