Forebody Wake Effects on Parachute Performance for Re entry Space Application

  • Mahendra Pratap DRDO-Aerial Delivery Research & Development Establishment, Agra - 282 001
  • Anil K. Agrawal Department of Mechanical Engineering, Indian Institute of Technology-BHU, Varanasi - 221 005
  • Subhash C. Sati DRDO-Aerial Delivery Research & Development Establishment, Agra - 282 001
  • Vipin Kumar DRDO-Aerial Delivery Research & Development Establishment, Agra - 282 001
Keywords: Wind tunnel test, Coefficient of drag, Aerodynamic interface data, Forebody, Parachute, Wake effect


Forebody generates its own wake that influences the performance of aerodynamic decelerators during the flights. Many parachute Jumpers have experienced the failure of an ejected pilot chute as the parachute canopy collapsed and fell back on the Jumper because of wake developed behind the Jumper. In the available literature, limited data is available to predict the exact loss of parachute drag in presence of the forebody (FB). The purpose of this paper is to generate a comprehensive aerodynamic data to study the behaviour of FB-parachute dynamics by conducting the wind tunnel experiments. Wind tunnel test has been carried out to establish the initial design parameters of aerodynamic parachute. The experiment was carried out on a scale down model of 20 degree conical ribbon drogue parachute and FB with and without each of them at a subsonic speed for studying dynamic stability characteristic for different orientation of FB. The test results indicate that to ensure adequate stability for the capsule to descend vertically at a low subsonic speed, a cluster of two drogue parachutes be used. Under such condition, the overall drag coefficient found to be above 0.50 providing not only a safe descends velocity but increasing reliability of
mission as well.


Gupta, Balraj. Aerial delivery systems and technologies. Def. Sci. J. 2010, 60(2), 124-136.

Knacke, T. W. Parachute recovery systems design manual. Para publishing, Santa Barbara, California, Report No. NWCTP6575, AD-A247 666, 1991.

Ewing, E. G.; Bixby, H.W. & Knacke, T. W. Recovery system design guide, Report No. AFFDL-TR-78-151, 1978, pp. 283-286 and pp. 375-378.

Eric, S. Ray. Test vehicle forebody wake effects on capsule parachute assembly system (CPAS). In proceeding of 24th AIAA Aerodynamic decelerator systems technology conference, 2017, Denver, Colorado.

Peterson, C.W. & Jonson, D.W. Reductions in parachute drag due to forebody wake effects. 2012.

Kolesar, R. & Yechout, T. Experimental investigation of NASA Orion pilot chute drag characteristics. In proceeding of 22nd AIAA Aerodynamic decelerator systems technology conference, AIAA paper No. 2013-1355, Daytona Beach, Florida, 2013.

Nuestadt, M.; Ericksen, R. E.; Guiteras, J.J. & Larrvee, J. A. A parachute recovery system dynamics analysis. J. Spacecraft Rockets, 1967, 4(3), 321-326.

Morris, A. L. Simulating new drop test vehicles and test techniques for the Orion CEV parachute assembly system. In proceeding of 21st AIAA Aerodynamic decelerator systems technology conference and seminar, AIAA paper 2011-2616. Dublin, Ireland, 2011, pp. 2011-2616.

Stuart, Phil C. Orion crew forebody pressure recovery fractions. Report No. EG-CAP-12-27, NASA/JSC EG3, 2012.

Guglieri, Giorgio. Parachute-payload system flight dynamics and trajectory simulation. Int. J. Aerospace Eng., 2012, Article id 182907, pp. 17.

NASA Space vehicle design criteria (structure). Deployable aerodynamic deceleration system. Report No. NASA-SP-8066, 1971, pp. 63.

Pratap, M.; Agrawal, A. K. & Kumar, S. Design and selection criteria of main parachute for re-entry space payload. Def. Sci. J., 2019, 69(6), 531-537.

Sengupta, A.; Stuart, P.; Ricardo M.; Bourland, G.; Schwing, A.; Longmire, E.; Hennings, E.; Sinclair, R. Subscale test program for the Orion conical ribbon drogue parachute. 21st AIAA Aerodynamic Decelerator Systems Technology Conference and Seminar, 2011, Dublin, Ireland, pp. 11-2509.

McVey, D.F.; Pepper, W.B. & Reed, J.F. A parametric wind tunnel study of ribbon parachutes. Report No. AIAA 75-1370, 1975, pp. 75-1370 .

Macha, J. An introduction to testing parachutes in wind tunnels. In 11th AIAA aerodynamic decelerator systems technology conference, San Diego, CA (USA), 2012, pp. 91-0858.

Poddar, K. Wind tunnel study of conical ribbon, ring slot and circular slotted HSP parachute. NWTF Technical Report, IIT Kanpur, India, 2011, pp. 142- 144.

Kumar, S.; Yadav, A. Jain, S.M.; Ahmed, M. &. Singh, S.P. Performance investigation of nylon-Kevlar ring-slot parachute. Def. Sci. J., 2014, 64(4), 406-410.

Knacke, T.W. The Apollo parachute landing system. In proceeding of 2nd AIAA Aerodynamic Decelerator System conference, USAF report FTC-TR-69-11, series: technical paper (Northrop ventura) : 131, EI Centro, Calif., 1968.

Sidana, M.L; Jain, J.C.; Pal, A. & Goel, A. Design, development and validation of a recovery system for 500 kg re-etry payload. In proceeding of 18th AIAA Aerodynamic Decelerator Systems Technology Conference and Seminar, AIAA 2005-1638, 2005, pp. 2005-1638.

How to Cite
Pratap, M., Agrawal, A., Sati, S. C., & Kumar, V. (2020). Forebody Wake Effects on Parachute Performance for Re entry Space Application. Defence Science Journal, 70(3), 223-230.
Aeronautical Systems

Most read articles by the same author(s)