1/28 Mano Prakash R., Manoj Kumar B., Lakshmi Narayanan Applied Aerodynamics Conference Modelling & Simulation In The Aerodynamic Design Process BRISTOL.
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Mano Prakash R., Manoj Kumar B., Lakshmi Narayanan
Applied Aerodynamics Conference Modelling & Simulation In The Aerodynamic Design Process
BRISTOL / 17 - 19 JULY 2012
Aerodynamic Performance Analysis of A Non Planar C Wing using Experimental
and Numerical Tools
Outline 1 Introduction
2 Computational Fluid Dynamics
3 Wind tunnel Testing
5
6 Conclusions and Recommendations
Radio – Controlled model
4 Induced drag comparison
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Outline 1 Introduction
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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 aircraft4/28
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.
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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 view6/28
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Outline
2 Computational Fluid Dynamics
CFD3D 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.
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Initial GeometryModel 1
Selection Criteria: Reference wing dimensions -Span = 500mm, Chord = 150mm, Aspect Ratio = 3.33
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Surface grids
Coarse Medium Fine
12782950Elements: 5626709 8757321
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Grids -Cut Section at 50% of span
Coarse Medium Fine
1.2 1.1 1.05Growth
rate
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Flow Field ConditionsReynolds Re = 3 × 105 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
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Force convergence
M∞ = 0.1, Re∞ = 3 × 105, α = 5o
CFD Results
Force coefficients do not asymptote on fine grid.13/28
Span1 Span2 Height1 702 753 804 855 425 1506 430 1457 435 1408 440 135
85
Dimensions (mm)Model
420 155
Final model
α
𝐿𝐷
Lift / Drag Vs. Angle of attack
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Outline
3 Wind tunnel Testing
Wind tunnel Subsonic wind tunnelHindustan College Of Engineering, Anna University, Chennai, India.
Tunnel type :
Open loop tunnel
Test section :
60cm × 60cm × 200cm
Velocity range:
0 – 80m/s
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Experimental set upModel
Material used:Fiberglass
Total pressure taps: 32
Manufacturing accuracy: ± 0.00012mm
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Results
𝐿𝐷
α
𝐿𝐷
α
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Outline
4 Induced drag comparison
Planar wing
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C-wing
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Interference factor b1 = 435mm b2 = 140mmh = 85mmb2/b1 = 0.32h/b1 = 0.2σ = 0.197 σ* = 0.98
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Comparison curve
α
𝑪𝑫𝑰
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Outline
5 Radio – Controlled model
ModelMaterials:Fuselage - Spad board reinforced with balsa wood.
Wing and tail plane - Coroplast reinforced with balsa wood.
Controls:Speed, aileron, elevator and rudder
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Outline
6 Conclusions and Recommendations
Conclusion and RecommendationsConclusions
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.27/28
THANK YOU
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