Fairing flap drag reduction mechanism ffdrm

1. International INTERNATIONAL Journal of Mechanical JOURNAL Engineering OF and MECHANICAL Technology (IJMET), ISSN ENGINEERING
0976 – 6340(Print),
ISSN 0976 – 6359(Online), Volume 5, Issue 9, September (2014), pp. 435-439 © IAEME
AND TECHNOLOGY (IJMET)
ISSN 0976 – 6340 (Print)
ISSN 0976 – 6359 (Online)
Volume 5, Issue 9, September (2014), pp. 435-439
© IAEME: www.iaeme.com/IJMET.asp
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IJMET
© I A E M E
FAIRING FLAP DRAG REDUCTION MECHANISM (FFDRM)
Santhosh Sivan. K1, Chandrasekar Sundaram2, Hari Krishnan. R3, Anirudh Srinivasan4
1, 2, 4(Department of Automobile Engineering, Anna University, MIT, Chennai, India)
3(Department of Aerospace Engineering, Anna University, MIT, Chennai, India)
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ABSTRACT
Motorcycles used in circuit racings are for demonstrating technological advancements of their
respective company for decades. The effects of various aerodynamic forces such lift, thrust, drag and
down force are necessary for maintaining equilibrium. Drag reduction techniques have been used in
Formula One. There have been no significant drag reduction techniques in place for motorcycle
competitions such as MotoGP, WSBK, etc. Motorcycle fairings provide a unique solution to reduce
drag but so far it has not been efficient. The fairings designed herewith can be used in straight-line
paths. Various designs of fairings are in place today but our design can reduce drag to a greater
extent than existing drag reduction techniques from the present.
Keywords: Aerodynamic Forces, Circuit Racings, Drag Reduction, Fairings and Motorcycles.
I. INTRODUCTION
Circuit racing is, predominantly, hosted for technological demonstrations. The current
research mainly focuses on gearbox design, engine efficiency and so. Motorcycle demonstration
companies are currently researching for drag reduction methods to enhance speed, especially during
straight-line paths. The increased speed is due to lesser drag and increased streamline flow around
the curvilinear pattern of the motorcycle. Currently, motorcycles used in circuit racings do not have
effective fairing design. It has been undermined due to its less scope in design.
II. MAIN SECTION
The fairing flap drag reduction mechanism designed here is solely to cater the circuit racing
purpose. The design parameter mainly addressed here is about decreasing drag especially during
straight-line path. Straight-line paths in the racetrack play a crucial role in determining the lap time
of a racer. The effect of the drag must be minimum in these straight-line paths to achieve the
maximum top speed in a short span of time. In the figure 2, the current design of a typical MotoGP

2. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print),
ISSN 0976 – 6359(Online), Volume 5, Issue 9, September (2014), pp. 435-439 © IAEME
motorcycle analyzed using Solidworks software is displayed. The drag coefficient of the fairing
design used in this motorcycle estimates to 0.6.
Figure 3: Proposed Fairing design Figure 4: Pressure analysis of proposed
436
Figure 1: Existing fairing design of a
typical race bike
Figure 2: Pressure analysis of the
existing fairing design
The Solidworks analysis used here displays the ineffectiveness of the fairing. It is highlighted
by yellow and red flow lines around the fairing. The drag during straight-line paths is greatly
increased and the motorist will experience higher drag when increasing the throttle. The pressure
increase is enormous. It is supported by the thick orange color from the above figure. The pressure
increase will negate any effect to increase acceleration. Thus, the motorist will be forced to use more
fuel to overcome this ‘increased’ drag to achieve maximum possible velocity within a short span of
time while cruising on straight-line paths.
III. PROPOSED SOLUTION
Various techniques for drag reduction in motorcycle fairings are in practice. Although they
have been innovative, they have not been effective. The proposed solution underscores the
importance of increased acceleration in straight-line race paths.
fairing
Here, the motorist must deploy the fairing flap drag reduction mechanism on the side of the
fairings electrically. This is almost similar to the Drag Reduction System (DRS) switch used in a F1
car. The fairing flap drag reduction system, when deployed during straight tracks, will incline at
lower angles. This inclination will tremendously streamline the flow around the corners. This flow

3. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print),
ISSN 0976 – 6359(Online), Volume 5, Issue 9, September (2014), pp. 435-439 © IAEME
pattern will thereby stabilize the bike i.e. an increase in throttle will result in equivalent increase in
acceleration. The proposed fairing design analyzed using SolidWorks is displayed below in figure 4.
The pressure analysis shows that the proposed fairing design reduces the resistance to airflow
considerably. When the fairing flap drag reduction mechanism is deployed, the corner airflow is
streamlined. Thus, the effective drag is highly decreased. The thick green patch on the fairing in the
figure 4 depicts it. This allows the throttle response to be effective.
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IV. MECHANISM
The fairing flap drag reduction mechanism consists of:
• Push-rod
• Trigger switch
• ECU
On encountering a straight-line path, the trigger switch is pressed. The trigger notifies the
ECU processor and it picks up the required flap signal from its input signals. This signal is processed
to the flap. Additionally, the flap is deployed by the push-rod. The figure 5 explains the above
mechanism in a simple manner.
Figure 5: Block diagram of Fairing Flap Drag Reduction Mechanism
V. VIRTUAL SIMULATION AND ANALYSIS
The proposed fairing flap drag reduction mechanism was analyzed in virtual simulation. The
mathematical model was used to plot the required graphs. The inferences from the graphs were used
to prove the effectiveness of the fairing flap drag reduction mechanism. The graphs plotted shows the
effective drag reduction, total pressure against the motorcycle and the velocity along the z-axis
schemes in the SolidWorks model.
From figure 8, it can be inferred that the drag coefficient is reduced from 0.6 to 0.51. The
decrease in drag increases the stability of the immediate airflow after the fairing flap drag reduction
mechanism is deployed. The drag reduction increases the effective acceleration and it increases the
speed of the motorcycle.

4. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print),
ISSN 0976 – 6359(Online), Volume 5, Issue 9, September (2014), pp. 435-439 © IAEME
438
Figure 6: Characteristic curve of
total pressure
Figure 8: Characteristic curve of
aerodynamic drag force
Figure 7: Characteristic curve of
velocity
Figure 9: Plotting of reduction in
Drag Coefficient
The total pressure and the velocity along the y-axis graphs state the efficiency of the proposed
fairing flap drag reduction mechanism after a particular iteration. The formula used to obtain the
graphs is:
The above formula is given as input to SolidWorks and the graph is plotted.
VI. CONCLUSION
The proposed fairing flap drag reduction mechanism therefore decreases the drag in straight
tracks on deployment. The force reduction due to the streamlined flow in front of the fairing
enhances the throttle response.
Figure 10: Computational Fluid Dynamic Analysis

5. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print),
ISSN 0976 – 6359(Online), Volume 5, Issue 9, September (2014), pp. 435-439 © IAEME
The fairing flap drag reduction mechanism provides an effective active response setting for
drag reduction. From the CFD analysis, it is implied that the fairing flap drag reduction mechanism
increases the acceleration and the top speed is attained in a short span of time while traversing
straight-line paths. The CFD analysis is displayed in figure 10. It can be inferred that pressure lines
produce a green striation on the deployed fairing flap drag reduction mechanism proving that drag
reduction increases the speed of the motorcycle with the drop in pressure.
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VII. REFERENCES
Books
[1] Vittore Cossalter, (2006) “Motorcycle Dynamics”, 2nd English edition.
[2] Jesse Russel Ronald Cohn, (2013) “Motorcycle Fairing”, Book on Demand, ISBN
5510714441, 9785510714449.
[3] P. E. Freathy J. D. Potter, (1980) “An Investigation of the Performance of a Motorcycle
Fairing”.
[4] Frederic P. Miller, Agnes F. Vandome John McBrewster, (2010) “Motorcycle Fairing”,
VDM Publishing, ISBN 6131609578, 9786131609572.
[5] Mark Gleason, (2001) “Vehicle Aerodynamics Design and Technology”, Society of
Automotive Engineers, ISBN 076800747X, 9780768007473.
[6] Andy Ibbott Keith Code, (2009) “Performance Riding Techniques: The MotoGP Manual
of Track Riding Skills”, Haynes Publishing PLC, 2nd illustrated edition, ISBN 1844256979,
9781844256976.
[7] Neil Spalding, (2010) “MotoGP Technology”, Haynes Publishing UK, 2nd illustrated edition,
ISBN 1844258343, 9781844258345.
[8] Manikandapirapu P.K, Srinivasa G.R, Sudhakar K.G, Madhu D., “Aerodynamic Flow
Simulation Model in Ducted Axial Fan using Simulink”, International Journal of Mechanical
Engineering Technology (IJMET), Volume 3, Issue 2, 2012, pp. 543 - 550, ISSN Print:
0976 – 6340, ISSN Online: 0976 – 6359.
[9] Yogesh Mahajan, A.A. Likhite and D.R. Peshwe, “Failure of Front Shock Absorber of a
Motorcycle”, International Journal of Advanced Research in Engineering Technology
(IJARET), Volume 5, Issue 5, 2014, pp. 141 - 148, ISSN Print: 0976-6480, ISSN Online:
0976-6499.