عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Performance of a aerospace vehicle or spacecraft during the re-entry have great dependency to flow-field physics around it. Aerothermodynamics heating in high velocity is highly dependent on geometry and flow-field physics. It is a big challenge of these vehicles for re-entry phase and engineers for reduction of these inappropriate effects use thermal protection systems with much expensive prices. In this Concern, the effects of flow control using counter flow axial jet ahead of a 2.6% scale model of Apollo capsule are investigated in order to decreasing the undesirable effects of aerothermodynamics heating. The aerodynamics performance of this capsule has been studied at free stream Mach number of 3.48 with 5 different flow rates of counter flow jet. The results show that two flow regimes can be seen by increasing the jet mass flow rate; Long Penetration Mode (LPM) and Short Penetration Mode (SPM). LPM that appears in low mass flow rates causes the increment of the shock-detachment distance, unsteadiness and flow oscillations and SPM that appears in high mass flow rates causes the decrement of the shock-detachment distance. Transition of LPM to SPM occurs in mass flow rate between 0.0145kg/s and 0.113kg/s. The results indicate that the counter flow jet decreases the drag about 80%. Moreover, the effects of excitation in counter flow pulsed jets at 1000Hz and 2000Hz frequency have been investigation for decrement of mass of fluid injection in this study. The results of this investigation shows that increment of excitation frequency to 2000Hz reduces drag near to 60%.
 Stadler, J. R., M. Inouye. “A Method of Reducing Heat Transfer to Blunt Bodies by Air Injection.” NACA, May, 1956.
 Ferri, A., M. H. Bloom. “Cooling by Jets Directed Upstream in Hypersonic Flow.” WADC Technical Note 56-382, Sept. 1957.
 Resler Jr., E. L., W. R. Sears. “The Prospects for Magneto-Aerodynamics.” Journal of the Aeronautical Sciences, Vol. 25, April 1958, pp. 235-245.
 Charczenco, N., K. W. Hennessey. “Investigation of a Retro-Rocket Exhausting from the Nose of a Blunt Body into a Supersonic Free Stream.” NASA TND-75 1, 1961.
 Warren, C. H. E. “An Experimental Investigation of the Effect of Ejecting a Coolant Gas at the Nose of a Bluff Body.” Journal of Fluid Mechanics, Vol. 2, No. 8, 1960, pp 400-417.
 Grimaud, J. E., L. C. McRee. “Experimental Data on Stagnation-Point Gas Injection Cooling on Hemispherical-Cone in a Hypersonic Arc Tunnel.” NASA TM X-983, July 1964.
 Beckwith, I. E., D. M. Bushnell. “Effect of Intermittent Water Injection on Aerodynamic Heating of a Sphere-Cone at Flight Velocities to 18000 Feet per Second.” NASA TM X-1128, 1965.
 Keyes, J. W., J. N. Hefner. “Effects of Forward-Facing Jets on Aerodynamic Characteristics of Blunt Configuration at Mach 6.” Journal of Spacecraft, Vol. 4, No. 4, April 1967, pp 533-534.
 Bushnell, D. M., J. K. Huffinan. “Forward Penetration of Liquid Water and Liquid Nitrogen from the Orifice at the Stagnation Point of a Hemispherically Blunted Body in Hypersonic Flow.” NASA TM X-1493, March1968.
 Jarvinen, P. O., R. H. Adams. “The Effects of Retrorockets on the Aerodynamic Characteristics of Conical Aeroshell Planetary Entry Vehicles.” AIAA Paper 70-219, January 1970.
 Shang, J. S., J. Hayes, K. Wurtzler, W. Strang. "Jet spike bifurcation in high speed flow." AIAA J., 39, 2001, pp. 1159-1165.
 Veukumar, B., G. Jagadeesh, K. P. J. Reddy, "Counterflow drag reduction by supersonic jet for a blunt body in hypersonic flow." Phys. Fluids, 18, 2006, pp. 81041-81044.
 Daso, E. O., W. Beaulieu, J. O. Hager. “Prediction of Drag Reduction in Supersonic and Hypersonic Flow with Counter-flow Jets.” AIAA 2002-5 115.
 Daso, E. O., V. E. Pritchett, T. S. Wang, et al. "Dynamics of shock dispersion and interactions in supersonic freestreams with counterflowing jets." AIAA Journal, 47(6), 2009, pp. 1313-1326.
 Chen, L. W., G. L. Wang, X. Y. Lu. "Numerical investigation of a jet front a blunt body opposing a supersonic flow." J. Fluid Mech., 684, 2011, pp. 85-110.
 Chao-Ying, Zh. "Numerical investigation on the drag and heat flux reduction of a supersonic reentry capsule with a counter-flow jet." Information Technology Journal 11(12), 2012, pp. 1705-1713.
 Zheng, Y., N. A. Ahmed, W. Zhang. “Heat dissipation using minimum counter flow jet ejection during spacecraft re-entry.” Procedia Engineering 49, 2012, pp. 271-279.
 Wilson, F., N. Santos. "Gas-Surface interaction impact on aerodynamic heating of a reentry Brazilian capsule." Combustion and Propulsion Laboratory (LPC), 2013, INPE 12630-000.
 Shyam, K., M. Singh, Sh. Jaiswal, G. Sh. Kanday. “Numerical Study on Aerodynamic Wave Drag Reduction by Counterflow Supersonic Jet in Hypersonic Flow.” International Journal of Science and Research, Vol. 4, Issue 3, March 2015.
 Wei, H. “A survey of drag and heat reduction in supersonic flows by a counterflowing jet and its combinations.” Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 16(7), 2015, pp. 551-561.