Effect of Endplate Shape on Performance and Stability of Wings-in Ground (WIG) Craft
Numerical analysis for the aerodynamic characteristics
of the WIG (wing-in ground effect) craft with highly cambered and
aspect ratio of one is performed to predict the ground effect for the
case of with- and without- lower-extension endplate. The analysis is
included varying angles of attack from 0 to10 deg. and ground
clearances from 5% of chord to 50%. Due to the ground effect, the lift
by rising in pressure on the lower surface is increased and the
influence of wing-tip vortices is decreased. These two significant
effects improve the lift-drag ratio. On the other hand, the endplate
prevents the high-pressure air escaping from the air cushion at the
wing tip and causes to increase the lift and lift-drag ratio further. It is
found from the visualization of computation results that two wing-tip
vortices are generated from each surface of the wing tip and their
strength are weak and diminished rapidly. Irodov-s criteria are also
evaluated to investigate the static height stability. The comparison of
Irodov-s criteria shows that the endplate improves the deviation of the
static height stability with respect to pitch angles and heights. As the
results, the endplate can improve the aerodynamic characteristics and
static height stability of wings in ground effect, simultaneously.
[1] http://www.se-technology.com.
[2] C. Wieselsberger, "Wing Resistance near the Ground," NACA TM No. 77,
1922.
[3] M.P. Fink and J.L. Lastinger, "Aerodynamic Characteristics of
Low-Aspect-Ratio Wings in Close Proximity to the Ground," NASA TN
D-926, 1961.
[4] A.W. Carter, "Effect of Ground Proximity on the Aerodynamic
Characteristics of Aspect-Ratio-1 Airfoils with and without End Plate,"
NASA TN D-970, 1961.
[5] M. R. Ahmed, "Aerodynamics of a NACA4412 Airfoil in Ground Effect,"
AIAA Journal, Vol. 45, No. 1, 2007.
[6] C. Hsiun and C. Chen, "Aerodynamic Characteristics of a
Two-Dimensional Airfoil with Ground Effect," J. of Aircraft, Vol. 33, No.
2, 1996.
[7] W. Rodi, Turbulence models and their applications in hydraulics-a state
art of review, Book Publication of International Association for Hydraulic
Research, Delft, Netherlands, 1984.
[8] L. H. Norris and W. C. Reynolds, Turbulent Channel Flow with a Moving
Wavy Boundary, Report. FM-10, Department of Mechanical Engineering,
Stanford University, CA, 1975.
[9] STAR-CD v4.00, Methodology, Computational Dynamics, Co., London.
U. K, 2006.
[10] S.V. Patankar, Numerical Heat Transfer and Fluid Flow, McGraw-Hill
Book Company, New York.
[11] Chang-Yeol Joh and Yang-Joon Kim, "Computational Aerodynamic
Analysis of Airfoil for WIG (Wing-In-Ground-Effect) - Craft," JSAS,
Vol. 32, No. 8 (Korean), 2004.
[12] M. R. Ahmed and S.D. Sharma, "An investigation on the aerodynamics of
a symmetrical airfoil in ground effect," Experimental Thermal and Fluid
Science, Vol. 29, pp. 633-647, 2005.
[13] N. A. Ahmed, and J. Goonaratne, "Lift Augmentation of a
Low-Aspect-Ratio Thick Wing in Ground Effect," J. Aircraft, Vol. 39, No.
2, 2002.
[14] I.G. Recant, "Wing-Tunnel Investitation of Ground Effect on Wing with
Flaps," NACA TN No. 705, 1939.
[15] R.D. Irodov, "Criteria of Longitudinal Stability of Ekranoplan," Ucheniye
Zapiski TSAGI, Vol. 1, No. 4, 1970.
[1] http://www.se-technology.com.
[2] C. Wieselsberger, "Wing Resistance near the Ground," NACA TM No. 77,
1922.
[3] M.P. Fink and J.L. Lastinger, "Aerodynamic Characteristics of
Low-Aspect-Ratio Wings in Close Proximity to the Ground," NASA TN
D-926, 1961.
[4] A.W. Carter, "Effect of Ground Proximity on the Aerodynamic
Characteristics of Aspect-Ratio-1 Airfoils with and without End Plate,"
NASA TN D-970, 1961.
[5] M. R. Ahmed, "Aerodynamics of a NACA4412 Airfoil in Ground Effect,"
AIAA Journal, Vol. 45, No. 1, 2007.
[6] C. Hsiun and C. Chen, "Aerodynamic Characteristics of a
Two-Dimensional Airfoil with Ground Effect," J. of Aircraft, Vol. 33, No.
2, 1996.
[7] W. Rodi, Turbulence models and their applications in hydraulics-a state
art of review, Book Publication of International Association for Hydraulic
Research, Delft, Netherlands, 1984.
[8] L. H. Norris and W. C. Reynolds, Turbulent Channel Flow with a Moving
Wavy Boundary, Report. FM-10, Department of Mechanical Engineering,
Stanford University, CA, 1975.
[9] STAR-CD v4.00, Methodology, Computational Dynamics, Co., London.
U. K, 2006.
[10] S.V. Patankar, Numerical Heat Transfer and Fluid Flow, McGraw-Hill
Book Company, New York.
[11] Chang-Yeol Joh and Yang-Joon Kim, "Computational Aerodynamic
Analysis of Airfoil for WIG (Wing-In-Ground-Effect) - Craft," JSAS,
Vol. 32, No. 8 (Korean), 2004.
[12] M. R. Ahmed and S.D. Sharma, "An investigation on the aerodynamics of
a symmetrical airfoil in ground effect," Experimental Thermal and Fluid
Science, Vol. 29, pp. 633-647, 2005.
[13] N. A. Ahmed, and J. Goonaratne, "Lift Augmentation of a
Low-Aspect-Ratio Thick Wing in Ground Effect," J. Aircraft, Vol. 39, No.
2, 2002.
[14] I.G. Recant, "Wing-Tunnel Investitation of Ground Effect on Wing with
Flaps," NACA TN No. 705, 1939.
[15] R.D. Irodov, "Criteria of Longitudinal Stability of Ekranoplan," Ucheniye
Zapiski TSAGI, Vol. 1, No. 4, 1970.
@article{"International Journal of Mechanical, Industrial and Aerospace Sciences:49773", author = "Kyoungwoo Park and Chol Ho Hong and Kwang Soo Kim and Juhee Lee", title = "Effect of Endplate Shape on Performance and Stability of Wings-in Ground (WIG) Craft", abstract = "Numerical analysis for the aerodynamic characteristics
of the WIG (wing-in ground effect) craft with highly cambered and
aspect ratio of one is performed to predict the ground effect for the
case of with- and without- lower-extension endplate. The analysis is
included varying angles of attack from 0 to10 deg. and ground
clearances from 5% of chord to 50%. Due to the ground effect, the lift
by rising in pressure on the lower surface is increased and the
influence of wing-tip vortices is decreased. These two significant
effects improve the lift-drag ratio. On the other hand, the endplate
prevents the high-pressure air escaping from the air cushion at the
wing tip and causes to increase the lift and lift-drag ratio further. It is
found from the visualization of computation results that two wing-tip
vortices are generated from each surface of the wing tip and their
strength are weak and diminished rapidly. Irodov-s criteria are also
evaluated to investigate the static height stability. The comparison of
Irodov-s criteria shows that the endplate improves the deviation of the
static height stability with respect to pitch angles and heights. As the
results, the endplate can improve the aerodynamic characteristics and
static height stability of wings in ground effect, simultaneously.", keywords = "WIG craft, Endplate, Ground Effect, Aerodynamics,
CFD, Lift-drag ratio, Static height stability.", volume = "2", number = "11", pages = "1187-7", }