Investigating Characteristics of an Exhaust Diffuser with Central Body on Products of Solid Fuel Combustion

Results of the experimental investigation of characteristics of the model of an exhaust diffuser with central body as applied to rocket engines of upper stages of launch vehicles and boosters with large geometrical expansion ratios are given. A model of the diffuser and nozzle channel is the reduced-size copy (on a scale of 1:3.77) of the full-scale engine channel. Testing was conducted on combustion products of the low-temperature solid fuel. A construction of the diffuser model is presented and its main constructive components and metrological support are described. The diffuser characteristics (a relative pressure at the nozzle exhaust section depending on a relative pressure in the gas-generator combustion chamber) are given for several diffuser configurations differing in length. A rate of the gas-generator pressure growth was also varied during the tests. The experimental data are analyzed and the comparative quantitative estimations of traditional diffuser types are performed.

References

[1] Il’inskii V.A. Issledovanie raketnykh dvigatelei na zhidkom toplive. [Study rocket liquid-fueled engine]. Moscow, Mir Publ., 1964. 454 p.

[2] Shishkov A.A., Silin B.M. Vysotnye ispytaniia reaktivnykh dvigatelei. [High-altitude test jet engines]. Moscow, Mashinostronie Publ., 1985, 208 p.

[3] Vorob’eva L.A., Dubinskii A.M., Tikhomirov B.K. Elements of the foreign countries stands intended for high-altitude test of rocket engines. Golovnoi otdel nauch.-tekh. inf. no. 8 [Head department of scientific and technical information]. Review no. 45, 1977. (In Russian, unpublished).

[4] Volkov N.N., Volkova L.I., Gurina I.N., Kozaev A. Sh. Experimental setup and technique for investigating characteristics of exhaust spike diffuser for try-out of rocket engines. Vestn. Mosk. Gos. Tekh. Univ.im. N.E. Baumana, Mashinostr. [Herald of the Bauman Moscow State Tech. Univ., Mech. Eng.], 2012, vol. 66, no. 4, p. 51-60 (in Russ.).

[5] Trusov B.G. Software system TERRA for the simulation phase and chemical equilibrium. Tr. XIV Mezhdunar. Konf. po Khim. Termodinamike [Proc. XIV Int. Conf. "Thermochemistry"]. S.-Pb., 2002.

[6] Study of supersonic flows with stall zones. Obzor TsAGI [Central Institute of Aerohydrodynamics Review]. Izdatel’skii otdel TsAGI Pnbl. M., 1977.