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Compressibility effects of unreacted propellant on thermally choked ram accelerator performance

Published online by Cambridge University Press:  11 December 2002

P. Bauer*
Affiliation:
Laboratoire de Combustion et de Détonique (UPR 9028 du CNRS) – ENSMA – BP 109, 86960 Futuroscope Cedex, France
C. Knowlen
Affiliation:
University of Washington (AERP) - Box 352250, Seattle, WA, 98195-2250, USA
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Abstract

Thrust calculations of the thermally choked ram accelerator propulsive mode based on quasi-steady, one-dimensional modeling of the flow process have been quite successful in predicting the experimental velocity-distance profile when real gas corrections are applied to the combustion products of propellants at initial fill pressures up to 8 MPa. A further refinement of the modeling takes into account real gas corrections for the initial state at higher fill pressures. It turns out that the Redlich-Kwong equation of state accurately determines the thermodynamic properties of the unreacted propellant for fill pressures up to at least 20 MPa. Using this equation of state for the calculation of the sound speed for a typical ${\rm CH}_4/{\rm O}_2/{\rm N}_2$ propellant provides a 15% higher value at 20 MPa than that predicted for an ideal gas; this increase significantly affects the operating characteristics of the ram accelerator at a given velocity. The corresponding thrust maximum increases by 30%. This corrected theory is most appropriate under conditions of high pressure operation at relatively low acceleration levels; i.e., less than 10 000 g. The corrections to the aerothermodynamic equations that are discussed in this paper are fully generalized and can be applied using any equation of state.

Keywords

Type
Research Article
Copyright
© EDP Sciences, 2003

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References

Bauer, P., Dunand, M., Presles, H.N., AIAA, Prog. Aeronaut. Astronaut. 133, 56 (1991)
P. Bauer, M. Dunand, H.N. Presles, O. Heuzé, Investigation on Extremely Dense Gaseous Explosives, Proc. of 17th Int. Symp. on Pyrotechnics Explosives, China Academic Publishers, Beijing, China, 1991, pp. 551-556
P. Bauer, H.N. Presles, O. Heuzé, J.F. Legendre, Prediction of Detonation Characteristics of Dense Gaseous Explosives on the Basis of Virial Equation of State, 20th Int. Pyrotechnics Seminar. Colorado Springs, CO, USA, 1994
Bauer, P., Knowlen, C., Bruckner, A.P., Henner, M., J. Phys. 10, 59 (2000)
Bauer, P., Knowlen, C., Bruckner, A.P., Shock Waves 8, 113 (1998) CrossRef
C. Bundy, C. Knowlen, A.P. Bruckner, Ram Accelerator Operating Characteristics at Fill Pressures Greater than 10 MPa, AIAA Paper 99-2261, 1999
C. Bundy, C. Knowlen, A.P. Bruckner, Investigation of Ram Accelerator Operation at Fill Pressures up to 20 MPa, AIAA Paper 2000-3231, 2000
C. Bundy, C. Knowlen, A.P. Bruckner, Ram Accelerator Operation at 15 to 20 MPa Fill Pressure, submitted to J. Prop. Power, 2002
Bruckner, A.P., Knowlen, C., Hetzberg, A., Bogdanoff, D.W., J. Prop. Power 7, 828 (1991) CrossRef
D.L. Buckwalter, C. Knowlen, A.P. Bruckner, RAM Accelerator Performance Code Incorporating Real Gas Effects, AIAA paper 96-2945, 1996
D.L. Buckwalter, C. Knowlen, A.P. Bruckner, Real Gas Effects on Ram Accelerator Analysis, AIAA paper 97-2894, 1997
W. Byers Brown, A. Amaee, Review of Equations of State of Fluids Valid to High Densities, Report # 39/1992, Dept. of Chemistry, University of Manchester, UK
Hertzberg, A., Bruckner, A.P., Knowlen, C., Shock Waves 1, 17 (1991) CrossRef
Heuzé, O., Phys. Rev. 34, 428 (1986) CrossRef
O. Heuzé, P. Bauer, H.N. Presles, C. Brochet, Equations of State For Detonation Products and their Incorporation into the QUATUOR Code, 8th Symp. (Int.) on Detonation, 1986, pp. 762-769
O. Heuzé, P. Bauer, H.N. Presles, QUATUOR: A Code for Computing Thermodynamic Properties of Detonation and Combustion Products, Seriep, Paris, 1987, pp. 91-96
Heuzé, O., Bauer, P., Presles, H.N., High Temp., High Pressures 19, 611 (1987)
Kemp, M.K., Thompson, R.E., Zigrang, D.J., J. Chem. Educ. 49, 802 (1975) CrossRef
C. Knowlen, A. Bruckner, Direct Launch Using Ram Accelerator Technology, Space Technology an Applications Int. Forum, edited by. M.S. El-Genk (Am. Inst. of Phys., 2001), pp. 583-588
R.W. Morris, E.A. Turek, Optimal Temperature-Dependence Parameters for the Redlich-Kwong Equation of State, Equations of State: Theories and Applications, edited by K.C. Chao, R.L. Robinson (Am. Chem. Soc., Washington, DC, 1986), pp. 389-397
Schultz, E., Knowlen, C., Bruckner, A.P., J. Prop. Power 16, 1040 (2000) CrossRef