Main Article Content
Abstract
The pressure gradient near the leading edge of an airfoil changes drastically in a short region. Sub - micron vibrations introduced in the zone of zero pressure gradient at a proper time in a pitching airfoil, mounted with active flexible wall actuator, alter the boundary layers. This in turn delays the onset of dynamic stall by around 2°.
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References
- Carr, L. W., "Progress in Analysis and Prediction of Dynamic Stall", Journal of Aircraft, Vol.25, No.1, 1988, pp.6-17.
- Gad-el-Hak, M., "Flow Control: The Future", Journal of Aircraft, Vol.38, No.3, 2001, pp.402-418.
- Alrefai, M. and Acharya, M., "Controlled LeadingEdge Suction for Management of Unsteady Separation Over Pitching Airfoils", AIAA Journal, Vol.34, No.11, November 1996, pp.2327-2336.
- Greenblatt, D. and Wygnaski, I., "Dynamic Stall Control by Periodic Excitation, Part 1: NACA 0015 Parametric Study", Journal of Aircraft, Vol.38, No.3, 2001, pp.430-438.
- Greenblatt, D., Nishri, B., Darabi, A. and Wygnaski, I., "Dynamic Stall Control by Periodic Excitation, Part 2: Mechanisms", Journal of Aircraft, Vol.38, No.3, 2001, pp.430-438.
- Hassan, A. A., "Applications of Zero Net Mass Jets for Enhanced Rotocraft Aerodynamic Performance", Journal of Aircraft, Vol.38, No.3, 2001, pp.478485.
- Chandrasekhara, M. S., Wilder, M. C. and Carr, L. W., "Compressible Dynamic Stall: Comparision of Two Approaches", Journal of Aircraft, Vol.38, No.3, 2001, pp.448-453.
- Chandrasekhara, M. S., Wilder, M. C. and Carr, L. W., "Compressible Dynamic Stall Control Using a Shape Adaptive Airfoil", AIAA Paper 99-0650, January 1999.
- Wehrmann, O. H., "Tollmein-Schlichting Waves under the Influence of a Flexible Wall", Physics of Fluids, 1965, pp.1389-1390.
- Breuer, K. S., Haritonidis, J. H. and Landahl, M. T., "The Control of Transient Disturbances in a Flat Plate Boundary Layer Through Active Wall Motion", Physics of Fluids A, Vol.1, No.3, 1989, pp.574 -582.
- Wilkinson, S. P. and Balasubramanian, R., "Turbulent Burst Control through Phase-locked Travelling Surface Depressions", AIAA Paper No.85-0536, 1985.
- Sinha, S. K., "System for Efficient Control of Separation using a Driven Flexible Wall", U.S. Patent 5, 961, 080, October 1999.
- Sinha, S. K. and Pal, D., "Controlling Unsteady separation with Acoustic Active Surfaces", AIAA Paper 94-0183, January 1994.
- Pal, D. and Sinha, S. K., "Controlling Unsteady Separation on a Cylinder with a Driven Flexible Wall", AIAA Journal, Vol.36, No.6, June 1998, pp.10231028.
- Sinha, S. K., "Flow Separation Control with Micro Flexural Wall Vibrations", Journal of Aircraft, Vol.38, No.3, 2001, pp.496-503.
- Sinha, S. K. and Zou, J., "On Controlling Flows with Micro-Vibratory Wall Motion", AIAA Paper 2000-
- , August 2000.
- Sinha, S. K., Pandey, M., Wang, H. and Pal, D., "Using an Array of Transducers under a Compliant
- Wall to Detect and Control Dynamic Stall on a Pitching Airfoil", AIAA Paper 98-0678, January 1998.
- Mangla, N. L., "Controlling Dynamic Stall with an Electrically Actuated Flexible Wall", Ph.D. Dissertation, Department of Mechanical Engineering, University of Mississippi, December 2002.
- Mangla, N. L. and Sinha, S. K., "An Interesting Phenomenon Observed in the Wind Tunnel", Journal
- of Aerospace Sciences and Technologies, Vol.67,No.3, August 2015, pp.338-445.
- Mangla, N. L. and Sinha , S. K., "Controlling Dynamic Stall Using an Active Flexible Wall", Journal
- of Aerospace Sciences and Technologies, Vol.69,No.1, February 2017, pp.55-64.
- Choudhari, P. G., Knight, D. D. and Visbal, M. R., "Two-Dimensional Unsteady Leading-Edge Separation on a Pitching Airfoil", AIAA Journal, Vol.32, No.41, April 1994, pp.673-682.
- Mangla, N. L., "Controlling Dynamic Stall with an Electrically Actuated Flexible Wall", VDM Verlag
- Dr. Muller Aktiengesellschaft and Co. KG, Germany, 2012, ISBN: 978-3-639-22963-9.
References
Carr, L. W., "Progress in Analysis and Prediction of Dynamic Stall", Journal of Aircraft, Vol.25, No.1, 1988, pp.6-17.
Gad-el-Hak, M., "Flow Control: The Future", Journal of Aircraft, Vol.38, No.3, 2001, pp.402-418.
Alrefai, M. and Acharya, M., "Controlled LeadingEdge Suction for Management of Unsteady Separation Over Pitching Airfoils", AIAA Journal, Vol.34, No.11, November 1996, pp.2327-2336.
Greenblatt, D. and Wygnaski, I., "Dynamic Stall Control by Periodic Excitation, Part 1: NACA 0015 Parametric Study", Journal of Aircraft, Vol.38, No.3, 2001, pp.430-438.
Greenblatt, D., Nishri, B., Darabi, A. and Wygnaski, I., "Dynamic Stall Control by Periodic Excitation, Part 2: Mechanisms", Journal of Aircraft, Vol.38, No.3, 2001, pp.430-438.
Hassan, A. A., "Applications of Zero Net Mass Jets for Enhanced Rotocraft Aerodynamic Performance", Journal of Aircraft, Vol.38, No.3, 2001, pp.478485.
Chandrasekhara, M. S., Wilder, M. C. and Carr, L. W., "Compressible Dynamic Stall: Comparision of Two Approaches", Journal of Aircraft, Vol.38, No.3, 2001, pp.448-453.
Chandrasekhara, M. S., Wilder, M. C. and Carr, L. W., "Compressible Dynamic Stall Control Using a Shape Adaptive Airfoil", AIAA Paper 99-0650, January 1999.
Wehrmann, O. H., "Tollmein-Schlichting Waves under the Influence of a Flexible Wall", Physics of Fluids, 1965, pp.1389-1390.
Breuer, K. S., Haritonidis, J. H. and Landahl, M. T., "The Control of Transient Disturbances in a Flat Plate Boundary Layer Through Active Wall Motion", Physics of Fluids A, Vol.1, No.3, 1989, pp.574 -582.
Wilkinson, S. P. and Balasubramanian, R., "Turbulent Burst Control through Phase-locked Travelling Surface Depressions", AIAA Paper No.85-0536, 1985.
Sinha, S. K., "System for Efficient Control of Separation using a Driven Flexible Wall", U.S. Patent 5, 961, 080, October 1999.
Sinha, S. K. and Pal, D., "Controlling Unsteady separation with Acoustic Active Surfaces", AIAA Paper 94-0183, January 1994.
Pal, D. and Sinha, S. K., "Controlling Unsteady Separation on a Cylinder with a Driven Flexible Wall", AIAA Journal, Vol.36, No.6, June 1998, pp.10231028.
Sinha, S. K., "Flow Separation Control with Micro Flexural Wall Vibrations", Journal of Aircraft, Vol.38, No.3, 2001, pp.496-503.
Sinha, S. K. and Zou, J., "On Controlling Flows with Micro-Vibratory Wall Motion", AIAA Paper 2000-
, August 2000.
Sinha, S. K., Pandey, M., Wang, H. and Pal, D., "Using an Array of Transducers under a Compliant
Wall to Detect and Control Dynamic Stall on a Pitching Airfoil", AIAA Paper 98-0678, January 1998.
Mangla, N. L., "Controlling Dynamic Stall with an Electrically Actuated Flexible Wall", Ph.D. Dissertation, Department of Mechanical Engineering, University of Mississippi, December 2002.
Mangla, N. L. and Sinha, S. K., "An Interesting Phenomenon Observed in the Wind Tunnel", Journal
of Aerospace Sciences and Technologies, Vol.67,No.3, August 2015, pp.338-445.
Mangla, N. L. and Sinha , S. K., "Controlling Dynamic Stall Using an Active Flexible Wall", Journal
of Aerospace Sciences and Technologies, Vol.69,No.1, February 2017, pp.55-64.
Choudhari, P. G., Knight, D. D. and Visbal, M. R., "Two-Dimensional Unsteady Leading-Edge Separation on a Pitching Airfoil", AIAA Journal, Vol.32, No.41, April 1994, pp.673-682.
Mangla, N. L., "Controlling Dynamic Stall with an Electrically Actuated Flexible Wall", VDM Verlag
Dr. Muller Aktiengesellschaft and Co. KG, Germany, 2012, ISBN: 978-3-639-22963-9.