1. Effect of Reynolds number on aerodynamics of airfoil
with gurney flap.
S.NO Name Roll No. Branch &
Section
1. Deshpande Siddhi Sadashiv 21951A2195 Aeronautical B
ExEEd-Prototype/Design Building
2. 2
Problem Statement and Industrial Need:
Problem Statement:
The less coefficient of lift minimize the speed of aircraft and long distance of
takeoff leads more consumption of fuel leads economical loss.
• To avoid such losses The Gurney flap is a simple device, such as a flat plate,
which can be easily attached to the pressure surface of an airfoil.
• It can effectively increase the lift coefficient of airfoils, wings, and aircrafts,
and shows great ability to shorten the takeoff/landing distance of the aircraft .
the gurney flap is used in low noise drone propeller, in racing car ,in sports
like formula 1, etc.
• thus analysis of effect of Reynolds number on aerodynamics of airfoil with
gurney flap plays an important role.
3. 3
Solution and Methodology:
Solution:
The Gurney flap is a simple device, such as a flat plate, which can be easily
attached to the pressure surface of an airfoil. It can effectively increase the lift
coefficient of airfoils, wings, and aircrafts, and shows great ability to shorten the
takeoff/landing distance of the aircraft. The gurney flap is used in low noise drone
propeller, in racing car ,in sports like formula 1, thus analysis of effect of Reynolds
number on aerodynamics of airfoil with gurney flap plays an important role.
Methodology:
• Geometry of the prototype :
airfoil to analyze the effect of variation in Reynolds number on the aerodynamics
of the airfoil without and with a Gurney flap of height of 4% chord length.
• Boundary Conditions Consider are:
The airfoil boundary is assigned as solid-wall with no-slip condition while inlet is
assigned as velocity inlet and outlet is assigned as pressure-outlet conditions.
Density based implicit solving scheme is used with the flow medium being air and
Mach number less than 0.3. Hence the fluid is assumed to be incompressible with
constant density of 1.225 kg/m3 and dynamic viscosity of 1.7894 × 10⁵ kg/m-s
4. 4
Uniqueness and Distinctive features:
• Gurney flaps are a practical solution for increasing lift if the accompanying
increase in drag is not a significant detractor.
• In addition to the download wings of racecars, applications that have been
considered include airfoil, wind turbine blades and turbomachinery.
• gurney flap extend perpendicularly from the lower surface of an airfoil near
its trailing edge increase the maximum lift coefficient, in some cases, by nearly
30%.
• A short separated region of increased pressure upstream of the Gurney flap is
accompanied by two counter-rotating vortices formed downstream, effectively
increasing the camber and shifting the Kutta condition to a point off of the
surface of the airfoil.
5. 5
Scalability and utility:
• In India the aviation industry is a growing and developing market thus the
device like flap are Used to enhancement of lift and reduce the takeoff
distance has wide scope
• Flaps are the used to enhance the lift and which reduces the take off
distance which is efficient in hilly regions for aircraft takeoff.
• Also the characterized low noise drone has effective role in defence
which is made by modifying the propeller by smaller gurney flap.
• The sports are also use the gurney flap to increase the speed
• In many different sectors the gurney flap is used ,thus it has a market to
grow more and more.
6. 6
Environmental sustainability:
• The less coefficient of lift minimize the speed of aircraft and long
distance of takeoff leads more consumption of fuel leads economical
loss Thus to avoid the we use the gurney flap which is attached to the
airfoil of aircraft
• Due to such a device the coefficient of lift is increased and the takeoff
distance also minimized so fuel consumption is less .
• The other case the gurney flap is used to low noise drone the small
flap are used to reduce the noise of drone .
• Similarly as aircraft the gurney flap are used in racing car to increase
the speed which covers more distance ;lesser fuel consumption.
9. Future Scope:
9
• Aviation industry is a growing and developing market thus the device like
flap are Used to enhancement of lift and reduce the takeoff distance has
wide scope
• Flaps are the used to enhance the lift and which reduces the take off
distance which is efficient in hilly regions for aircraft takeoff.
• Also the characterized low noise drone has effective role in defense
which is made by modifying the propeller by smaller gurney flap.
• The sports like racing car also use the gurney flap to increase the speed
• In many different sectors the gurney flap is used, and the aviation market
is growing more and more so it has wide scope in future.
10. 10
Learning’s from prototype:
• I learn the basic concepts of Drag, lift, coefficient of lift, Reynolds number more
clearly.
• Also the concept of boundary layer separation and role of flap in the aircraft
What is gurney flap and applications of gurney flap and it’s benefits of gurney
flap are able to understand.
• Even The concept of height of gurney flap and the relation between the chord
length and gurney flap
• The concept of Kutta condition and stall angle ,angle of attack are learnt
• I learn the importance of gurney flap in aircraft and racing cars and sports like
formula 1 .
11. 11
References
1. R. W. Prouty, Helicopter Aerodynamics, vol. 2, Philips Publishing, 1985.
2. R. H. Liebeck, “Design of subsonic airfoils for high lift, "Journal of Aircraft, vol. 1,
no. 9, pp. 547–561, 1978
3. Y. C. Li, J. J. Wang, and P. F. Zhang, “Effects of Gurney flaps on a NACA0012
airfoil,” Flow, Turbulence and Combustion, vol. 68,no. 1, pp. 27–39, 2002.
4. J. J. Wang, Y. C. Li, and K.-S. Choi, “Gurney flap-Lift enhancement,
mechanisms and applications,” Progress in Aerospace Sciences, vol. 44, no. 1,
pp. 22–47, 2008.
5. T. J. Mueller and S. M. Batill, “Experimental studies of separation on a two-
dimensional the airfoil at low Reynolds numbers,”AIAA journal, vol. 20, no. 4,
pp. 457–463, 1982.
6. M. S. Selig, J. F. Donovan, and D. B. Fraser, Airfoils at Low Speeds, Soartech 8,
Soartech Publications, Virginia Beach, Va,USA, 1989.
7. L. W. Traub and G. Agarwal, “Aerodynamic characteristics of a gurney/jet flap at
low Reynolds numbers,” Journal of Aircraft, vol.45, no. 2, pp. 424–429, 2008.
8. T. J. Mueller, “Aerodynamic measurements at low Reynolds numbers for fixed
wing micro-air vehicles,” in Proceedings of the Special Course on Development
and Operations of UAVs for Military and Civil Applications, Rhode-Saint-Genese
Belgium, September 1999.
