Open Access Open Access  Restricted Access Subscription Access
Open Access Open Access Open Access  Restricted Access Restricted Access Subscription Access

Bleed System for Safe Release of Weapons from Combat Aircraft


Affiliations
1 Bhubaneswar Engineering College, Bhubaneswar, Odisha, India
     

   Subscribe/Renew Journal


An idea was carried out on an open cavity having a free stream Mach number of 0.8. The main objective of the present study is to design a passive venting that connects the high pressure region on the rear wall to a low pressure region downstream of the cavity. The baseline condition shows that the cavity flow oscillate with the total amplitude of 155 m. The vortex clipping which is responsible for the self-sustained nature of the cavity flow and the corresponding time history of the pressure on the cavity rear wall is discussed. A cross correlation analysis was carried out between the pressure history at the points on the rear wall of the cavity and the ones on the wall downstream of the cavity. Two points that defines the passive venting were identified based on the rear wall Overall Sound Pressure Level (OASPL) and the minimum time lag computed by cross correlation. The venting is shown to reduce the cavity oscillations and the rear wall pressure is shown to reach a steady state value which is desired in the perception of low cavity noise that can be used to reduce the structural loads and the acoustic loads on electronic components kept near the cavity.

Keywords

Bay, Cavity, Combat, Venting.
User
Subscription Login to verify subscription
Notifications
Font Size

  • J. E. Rossiter, “Wind tunnel experiments on the flow over rectangular cavities at subsonic and transonic speeds,” Technical Report 64037, Royal Aircraft Establishment, October 1964.
  • R. L. Stallings, “Store separation from cavities at supersonic flight speeds,” Journal of Spacecraft and Rockets, vol. 20, no. 2, pp. 129-132, March-April 1983.
  • A. B. Blair, and R. L. Stallings, “Cavity door effects on aerodynamic loads of stores separating from cavities,” Journal of Aircraft, vol. 26, no. 7, pp. 615-620, July 1989.
  • F. J. Wilcox Jr., “Experimental measurements of internal store separation characteristics at supersonic speeds,” NASA Technical Report, 1990.
  • D. P. Rizzetta, and M.. R. Visbal, “Large-eddy simulation of supersonic cavity flowfields including flow control,” AIAA Journal, vol. 41, no. 8, pp. 1452-1462, August 2003.
  • P. R. Spalart, “Strategies for turbulence modelling and simulations,” International Journal of Heat and Fluid Flow, vol. 21, no. 3, pp. 252-263, June 2000.
  • J. A. Ross, and J. W. Peto, “The effect of cavity shaping, front spoilers and ceiling bleed on loads acting on stores, and on the unsteady environment within weapon bays,” Technical Report, QinetiQ, March 1997.
  • L. Cattafesta, D. R. Williams, C. W. Rowley, and F. Alvi, “Review of active control of flow-induced cavity resonance,” In 33rd AIAA Fluid Dynamics Conference, AIAA Paper 2003-3567, June 2003.
  • K. J. Badcock, B. E. Richards, and M. A. Woodgate, “Elements of computational fluid dynamics on block structured grids using implicit solvers,” Progress in Aerospace Sciences, vol. 36, no. 5-6, pp. 351-392, 2000.
  • J. A. Ross, “PIV measurements of the flowfields in an aerodynamically deep cavity,” Private Communication, May 2002.

Abstract Views: 10

PDF Views: 0




  • Bleed System for Safe Release of Weapons from Combat Aircraft

Abstract Views: 10  |  PDF Views: 0

Authors

Jaydev Samal
Bhubaneswar Engineering College, Bhubaneswar, Odisha, India
Kali Prasad Samantra
Bhubaneswar Engineering College, Bhubaneswar, Odisha, India
Satyajit Pat
Bhubaneswar Engineering College, Bhubaneswar, Odisha, India
Amit Nayak
Bhubaneswar Engineering College, Bhubaneswar, Odisha, India
S. K. Samal
Bhubaneswar Engineering College, Bhubaneswar, Odisha, India

Abstract


An idea was carried out on an open cavity having a free stream Mach number of 0.8. The main objective of the present study is to design a passive venting that connects the high pressure region on the rear wall to a low pressure region downstream of the cavity. The baseline condition shows that the cavity flow oscillate with the total amplitude of 155 m. The vortex clipping which is responsible for the self-sustained nature of the cavity flow and the corresponding time history of the pressure on the cavity rear wall is discussed. A cross correlation analysis was carried out between the pressure history at the points on the rear wall of the cavity and the ones on the wall downstream of the cavity. Two points that defines the passive venting were identified based on the rear wall Overall Sound Pressure Level (OASPL) and the minimum time lag computed by cross correlation. The venting is shown to reduce the cavity oscillations and the rear wall pressure is shown to reach a steady state value which is desired in the perception of low cavity noise that can be used to reduce the structural loads and the acoustic loads on electronic components kept near the cavity.

Keywords


Bay, Cavity, Combat, Venting.

References