A Review on Surface Modification of Airfoils Using
Dimples
Rubiat Mustak
To cite this version:
Rubiat Mustak. A Review on Surface Modification of Airfoils Using Dimples. International
Journal of Research, IJR, 2017, 4 (5), pp.842-846. .
HAL Id: hal-01513638
https://hal.archives-ouvertes.fr/hal-01513638
Submitted on 25 Apr 2017
HAL is a multi-disciplinary open access
archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.
L’archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d’enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.
International Journal of Research
Available at
https://edupediapublications.org/journals
p-I SSN: 2 3 4 8 -6 8 4 8
e-I SSN: 2 3 4 8 -7 9 5 X
Vol ume 0 4 I s s ue 0 5
Apr i l 2 0 1 7
A Review on Surface Modification of Airfoils
Using Dimples
Rubiat Mustak1*
1
Department of Mechanical Engineering, Khulna University of Engineering & Technology, Khulna9203, Bangladesh.
E-mail: [email protected]
A b s t ract :
An airfoil is a cross section of airplanes wings.
Wings of airplanes produce lift by creating pressure
difference between upper and lower surface of
wings. This so called lift enables the airplanes to fly
helps them remain high in the sky. One of the major
problems that an airplane experienced is flow
separation .Which causes the reduction of lift and
increment of drag. Drag is the resisting force of air.
A lot of researchers working hard since few decades
to minimize this flow separation effect. As a result of
their hard working concept of vortex generator have
been developed .Which delays the boundary layer
separation. Though there are various types of vortex
generators. In the present review a special type of
vortex generator namely dimple is focused. Since last
half of decades investigations related to dimples
grew the attention of many researchers .A lot of
numerical and experimental investigations have been
conducted by several researchers around the world
related to dimples effect on airplanes wings cross
section or airfoils. The outcomes of those
investigations are extremely tremendous. Those
outcomes indicate that dimples of different size and
shape can play a vital role in designing of airplanes
wings. This present study or review try to sum up all
of those researches in a nut shell.
Key wo rd s
Airfoil, Dimple, Investigation, Review, Wing, Wind
Tunnel.
1. Introduction
From the earliest starting point of human race,
man has dependably longed for flying and on
December 17, 1903 Wright siblings gave human race
new wings and sought after ceaseless attempts in this
field. Presently we have advanced to extraordinary
degree in air yet at the same time after so much has
Available online:
been done there are sure requirements restricting us
[1]. Opportunity noticeable all around is as yet not
finish. Consistent endeavors are being made to build
opportunity in air, be it speed, size or mobility. From
business jetliners to supersonic contenders, there has
been an exponential development in the avionics
business [2]. Still there is immense degree for further
upgrades. Here is a review that makes one such
attempt. At present, various types of surface changes
are being contemplated to enhance the mobility of
the airplane. One of them is Vortex generator .Which
delays the boundary layer separation. Though there
are various types of vortex generators. In the present
review a special type of vortex generator namely
dimple is focused. They work as a same manner of
vortex generators [2].But are not actually
conventional one. They create turbulence thereby
delaying flow separation and hence increasing the
overall performance of airplanes wings [2].
2. Concept of Dimples
The Concept of dimples came from golf balls [3].
Golf balls have inner impressions in form of dimples
on their outer surfaces. These dimples help golf balls
to reduce drag. Drag is resisting force from air. A
liquid streaming over a protest tends to drag the
question along its stream bearing. A question going
through a liquid which is stationary there is a
propensity to back the protest off. For a stationary
question in a liquid which is streaming there is an
inclination to move the protest in the liquid
streaming heading .These propensities of streaming
liquid is known as drag. While traveling through air
planes additionally subjected to a few drags. As
dimples reduce drag of golf ball they can be useful
on reducing wings drag. That grows the attention of
several researchers about dimple. There were a lot of
experiments and numerical investigations have been
conducted by several researchers around the world
on dimpled effect on airplane wings.
https://edupediapublications.org/journals/index.php/IJR/
Page | 8 4 2
International Journal of Research
Available at
https://edupediapublications.org/journals
Fig 2.1.Inner Impressions in form of d imp les o n
g o lf b all
Fig 2.2. Inner Impressions in form of d imp les o n
airp lan e win g s cro s s s ect io n
3. Numerical Investigations
Deepanshu Srivastav in 2012 presents a research
paper on Flow Control over Airfoils using Different
Shaped Dimples at International Conference on Fluid
Dynamics and Thermodynamics Technologies . He
performed a CFD investigation in 3-D by taking a
fragment of the airfoil with one dimple on it. He
prepared his CAD model using CatiaV5 R18 and
simulations were carried out in Comsol 3.4 and
Comsol 4.2a.His results were in agreement that
dimples at first glance on wing model does not
influence the weight drag much since it is now
streamlined fit as a fiddle however it can influence
its optimal design when the airfoil is at various angle
of attcak. This venture confirms if the dimples that
decrease a golf ball's drag, can additionally modify
stream elements around airfoil for better streamlined
productivity [4].
M. Moses Devaprasanna, N. Maheswaran, M.
Harish and Prof. A. Sankaran in 2016 published their
research paper on CFD study on aerodynamic effects
of dimples on aircraft wings in International Journal
of Engineering & Science Research. There venture
likewise includes in decreasing the take-off
Available online:
p-I SSN: 2 3 4 8 -6 8 4 8
e-I SSN: 2 3 4 8 -7 9 5 X
Vol ume 0 4 I s s ue 0 5
Apr i l 2 0 1 7
separation by accomplishing high Coefficient of lift
at higher angle of attack [5].
P. Booma Devi, Dilip A. Shah in 2016 published
their article on Computational Analysis of Cavity
Effect over Aircraft Wing in International Journal of
Mechanical, Aerospace, Industrial, Mechatronic and
Manufacturing Engineering. For their study the wing
was demonstrated in CATIA V5R20 and
examinations were done utilizing ANSYS CFX.
Triangle and square shapes dimples were considered.
They show that efficiency improvement can be
achieved by improving the maximum lift co-efficient
or by reducing the drag co-efficient. Their
computational outcomes demonstrate an expansion
in lift. Presentation of dimple is a powerful
controlling strategy to increment in angle of stall and
lift coefficient [6].
E. Livya, G. Anitha, P. Valli published their
research paper on Aerodynamic Analysis of Dimple
Effect on Aircraft Wing in International Journal of
Mechanical, Aerospace, Industrial, Mechatronic and
Manufacturing
Engineering.
Their
venture
incorporates both computational and exploratory
investigation of dimple impact on airplanes wing,
utilizing NACA 0018 airfoil. Dimple states of Semicircle, hexagon, cylinder, square are chosen for the
investigation. Their results showed the dimple
impact by expanding L/D proportion and
consequently giving the most extreme streamlined
productivity, which gives the upgraded execution for
the airplane [7].
Thamodharan B , Shaik Mohamed Nagutha G,
Sacraties A , Devaki P in 2016 share their article on
Numerical Analysis of Effect of Dimples on Aerodynamics of an Airfoil in International Conference
on Explorations and Innovations in Engineering &
Technology (ICEIET - 2016).They increase the stall
angle by deferring the stream detachment utilizing
dimples at different areas on the suction surface of
the airfoil [8].
4. Construction of Dimpled Airfoils
An airfoil is a cross segment of plane’s wings. It
is especially troublesome for a specialist to play out
his test all in all air ship wing .So a test utilizing little
cross segment of wings or airfoils is performed by
scientists. For trial purposes airfoils require to be
built. For building a genuine airfoil an airfoil profile
is required. For getting airfoil profiles directions are
required. There are numerous accessible online
hotspots for these directions [9].
Rubiat Mustak et al. in their published paper in
Asia Pacific Journal of Engineering Science and
Technology have shown a simple way of
constructing dimpled airfoils. They Utilized C
programming with the assistance of NACA gave
conditions. A summed up source code was outlined
https://edupediapublications.org/journals/index.php/IJR/
Page | 8 4 3
International Journal of Research
Available at
https://edupediapublications.org/journals
p-I SSN: 2 3 4 8 -6 8 4 8
e-I SSN: 2 3 4 8 -7 9 5 X
Vol ume 0 4 I s s ue 0 5
Apr i l 2 0 1 7
.Which will give directions to planning any NACA
four digit airfoil profiles .With the assistance of this
obtained profile the wing model was built utilizing
solid works software .The harmony of consistent
surface airfoil is 21 cm and the traverse is likewise
21 cm. The airfoil profile taken for the model
development was NACA-4415 which is a four digit
cambered
airfoil
.Their
work
additionally
demonstrate a few figures of an airfoil by applying
certain surface alterations in form of dimples [10].
Some of constructed dimpled airfoils are shown
below.
Fig.4.4 Arranged model with combination of
hexagonal and circular dimples
5. Experimental Investigations
Fig. 4.1 Arranged model with outward
spherical dimples
Several experimental investigation papers were
published by Rubiat Mustak et al. Many of them
were performed in Aerodynamics Laboratory of
Department of Mechanical Engineering at Khulna
University of Engineering and Technology with
subsonic wind tunnel of 1 m× 1 m rectangular test
area.
In 2015 Md. Amzad Hossain et al. published a
research paper on Experimental Study of
Aerodynamic Characteristics Of Airfoils Using
Different Shaped Dimples in The International
Journal Of Engineering And Science (IJES) where
they claim that the stream partition on the airfoil can
be postponed by utilizing the dimples on the upper
surface and the lift force and stall angle of attack are
additionally expanded surprisingly. On that research
it was also claimed that at 16° angle of attack the
stream is isolated from the upper surface if there
should be an occurrence of dimpled surface [1]
.Where the phenomena likely to occur in regular
surface at 12° angle of attack [12]. It was also shown
that lift force will be more and drag force will be less
in case of dimpled surface.
Fig.4.2 Arranged model with hexagonal
dimples
Fig 5.1 More lift force is o b t ain ed b y d imp led
airfo il
Fig.4.3 Arranged model with circular dimples
Available online:
https://edupediapublications.org/journals/index.php/IJR/
Page | 8 4 4
International Journal of Research
Available at
https://edupediapublications.org/journals
p-I SSN: 2 3 4 8 -6 8 4 8
e-I SSN: 2 3 4 8 -7 9 5 X
Vol ume 0 4 I s s ue 0 5
Apr i l 2 0 1 7
aircraft. Enhanced aerodynamic efficiency is critical
to both business and military aircrafts. For business
airplane, enhanced optimal design decreases working
expenses. So future research related to dimpled
airfoil have a probability of great impact in aircraft
manufacturing.
7. References
[1]
Fig 5.2 Dimpled airfoils subject ed t o les s d rag
Rubiat Mustak et al. claim the same results as Md.
Amzad Hossain in the 3rd International Conference
on Mechanical Engineering and Renewable Energy
2015 (ICMERE2015) hosted by Chittagong
University of Engineering & Technology (CUET) in
Chittagong, Bangladesh [3].
Rubiat Mustak et al. published another paper on
Improvement of Aerodynamic Characteristics of an
Airfoil by Surface Modification in American Journal
of Engineering Research (AJER) in 2017.Where the
surface modification that were considered on that
research was hexagonal dimples on the wing model.
They claim that the flow separation on the airfoil can
be delayed by using hexagonal dimples on the upper
surface. On that research it was also claimed that at
16° angle of attack the stream is isolated from the
upper surface if there should be an occurrence of
dimpled surface [2] .Where the phenomena likely to
occur in regular surface at 12° angle of attack [12]. It
was also shown that lift force will be more and drag
force will be less in case of hexagonal dimpled
surface.
The same results were claimed by Mohammad
Mashud et al. in International Conference on
Mechanical Engineering and Advanced Materials
2015 hosted by university of Sabah Malaysia (USM)
in Kota Kinabalu, Sabah,Malaysia[16].
All of the above studies indicate that dimples which
reduce the drag of golf balls can reduce the drag of
airfoils [15].
[2]
[3]
[4]
[5]
[6]
[7]
[8]
6. Conclusions
From the above study it is seen that dimples which
reduce the drag of golf balls can reduce the drag of
airfoils. Several researchers around the world have
shown both in numerical and experimental ways that
dimples plays an important role in drag reduction.
They also assist to have more lift hence more lift to
drag ratio. Dimpled airfoils make the aircrafts more
maneuverable.
They
increase
aerodynamic
efficiencies. Aerodynamic efficiency is one of the
key parameters that decides the weight and cost of an
Available online:
[9]
[10]
M d.Amzad Hossain,M d. Nizam Uddin,Rubiat
M ustak,M .M ashud,“ Experimental Study of
Aerodynamic Characteristics Of Airfoils Using
Different Shaped Dimples”, The International
Journal Of Engineering And Science (IJES)
,Volume 4, Issue 1, Pages PP.13-17 ,2015
Rubiat M ustak, M d. Harun-Or-Rashid M olla,
M ohammad
M ashud,
“Improvement
of
Aerodynamic Characteristics of an Airfoil by
Surface M odification”, American Journal of
Engineering Research (AJER),Volume 6,Issue
3,PP.07-14,2017
Rubiat M ustak, M D. Nizam Uddin, M ohammad
M ashud,“ Effect of different shaped dimp les on
airfoils”, Proceedings of the 3rd International
Conference on M echanical Engineering and
Renewable Energy 2015 (ICM ERE2015), 26 –
29 November, 2015, Chittagong, Bangladesh
Deepenshu Srivastav (2012), “Flow Control
Over Airfoils Using Different Shaped Dimples”,
International Conference on Fluid Dynamics and
Thermodynamics Technologies (FDTT) IPCSIT
Vol.33 IACSIT Press, Singapore
M . M oses Devaprasanna, N. M aheswaran, M .
Harish and Prof. A. Sankaran(2016),CFD study
on aerodynamic effects of dimples on aircraft
wings, International Journal of Engineering &
Science
Research,Volume-6,Issue-11,Pages
pp.245-248,2016
P.
Booma
Devi,
Dilip
A.
Shah
(2016),Computational Analysis of Cavity Effect
over Aircraft Wing, International Journal of
M echanical, Aerospace, Industrial, M echatronic
and
M anufacturing
Engineering,Volume10,Issue-4,2016
Livya. E, Anitha. G and Valli. P “Aerodynamic
analysis of dimple effect over aircraft wing”
International journal of mechanical aerospace
industrial and mechatronics engineering, Vol-9.
No 2, 2015 pp 350-353.
Thamodharan B, Shaik M ohamed Nagutha
G,Sacraties A , Devaki P (2016),Numerical
Analysis of Effect of Dimples on Aero-dynamics
of an Airfoil, International Conference on
Explorations and Innovations in Engineering &
Technology (ICEIET - 2016).
Rubiat M ustak,“ Development of a Generalized
Source Code for NACA Four Digit Airfoils”,
International Journal of Research(IJR),Volume4,Issue-5,Pages PP.285-290,April,2017
Rubiat M ustak, M d. Habib Ullah Khan, M d.
Harun-Or-Rashid
M olla,“
Design
and
construction of NACA-4415 airfoil with various
shaped surface modifications”, Asia Pacific
Journal
of
Engineering
Science
and
https://edupediapublications.org/journals/index.php/IJR/
Page | 8 4 5
International Journal of Research
Available at
https://edupediapublications.org/journals
[11]
[12]
[13]
[14]
[15]
[16]
p-I SSN: 2 3 4 8 -6 8 4 8
e-I SSN: 2 3 4 8 -7 9 5 X
Vol ume 0 4 I s s ue 0 5
Apr i l 2 0 1 7
Technology(APJEST),Volume-3,Issue-1,PP.2838,2017.
Dr. P. N. M odi & Dr. S. M Seth, "Hydraulics and
Fluid M echanics Including M achines" (In SI
Unit), new edition 2005-2006, Standard Book
House
John D. Anderson, J.R," Introduction to Flight
Dynamics", Third Edition, M c Graw-Hill
International Editions, Aerospace Science Series
E. L. Houghton and P. W. Carpenter,
"Aerodynamics
for Engineering Students
",Fourth Edition, Edward Arnold Publisher
Charles E. Dole," Flight Theory and
Aerodynamics ",A Wiley Inter science
Publication.
Davies, J.M.,“ The aerodynamics of golf
balls”, J of Applied Physics, 1949, 20, (9),
PP 821-828.
M ohammad
M ashud,
Rubiat
M ustak,“
Experimental
Study
of
Aerodynamic
Characteristics of Airfoils Using Hexagonal
Shaped Dimples”, International Conference on
M echanical Engineering and Advanced M aterials
2015,3-4 December, 2015, Kota Kinabalu,
Sabah,M alaysia
Available online:
https://edupediapublications.org/journals/index.php/IJR/
Page | 8 4 6