TECHNICAL MECHANICS
ISSN (Print): 1561-9184, ISSN (Online): 2616-6380

HOME    ABOUT THIS JOURNAL    EDITORIAL BOARD    GUIDE FOR AUTHORS    CURRENT    JOURNAL ISSUES    CONTACTS

UDC 621.671: 532.528

Technical mechanics, 2017, 2, 12 - 19

HYDRODYNAMIC MODEL OF CAVITATION OSCILLATION FOR MODELLING DYNAMIC PROCESSES WITHIN PUMP SYSTEMS AT HIGH CAVITATION NUMBER

DOI: https://doi.org/10.15407/itm2017.02.012

S. I. Dolgopolov

S. I. Dolgopolov
Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine
Ukraine

      The paper deals with mathematical modelling the low-frequency dynamic processes within liquid rocket engines (LRE). Attention in the work is devoted to developing the mathematical model of the cavitation oscillation for modelling the dynamic processes within the pump systems at the high cavitation number. To attain this objective, the experimental and calculated dependences of the cavities elasticity on the pump parameters at the high cavitation number are corrected including the cavitation number resulting in cavities within the centrifugalimpeller pump. The dependence of the cavities volume on the operating conditions of the pump is determined using the experimental and calculated method of the measurement of the elasticity and the cavities volume within the centrifugal-impeller pumps. The dynamic cavity equation is derived in the differential form. In the calculations of LRE starting, it allows to use the derived analytical dependences for a nonlinear hydrodynamic model and to take into account the fluid compliance (under cavitation-free conditions of the pump operation) within the supply line without changing the structure of the mathematical model of the LRE starting and discontinuous changing the values of the equation coefficients. The research results can be used to take into account the cavitation effects within the pumps for calculating LRE starting.

liquid rocket engine, centrifugal-impeller pump, cavitation, cavitation oscillation, cavitation number, starting, mathematical modelling

1. Pylypenko V. V., Zadontsev V. A., Natanzon M. S. Cavitation Oscillation and Dynamics of Hydraulic Systems. Moscow.: Mashinostroyeniye, 1977. 352 pp. (in Russian).

2. Pylypenko V. V. Cavitation of Self-Oscillation. Kiev: Naukova Dumka, 1989. 316 pp. (in Russian).

3. Shevyakov A. A., Kalnin V. M., Naumenkova M. V., Dyatlov V. G. Theory of Automatic Control of Rocket Engines. Moscow: Mashinostroyeniye, 1978. 288 pp. (in Russian).

4. Belyaev Ye. N., Chvanov V. K., Chervakov V. V. Mathematical Modelling of Operating Process of Liquid Rocket Engines. Moscow: MAI, 1999. 228 pp. (in Russian).

5. Pylypenko V. V. On the mechanism of self-excitation of cavitation self-oscillation in the system of centrifugal-impeller pump and ducts without reverse currents. Kosmicheckie Issledovania na Ukraine. 1975. Iss. 7. Pp. 3- 10. (in Russian).

6. Pylypenko V. V. Experimental and calculated technique for determination of elasticity and volume of cavitation cavities in centrifugal-impeller pumps. Izvestia AN SSSR. Energetika i Transport. 1976. No. 3. Pp. 131-139 (in Russian).

7. Grigoriev Yu. Ye., Pylypenko V. V. Experimental and calculated determination of cavitation cavities elasticity in centrifugal-impeller pumps under conditions of reverse flows. Dynamics of Pump Systems. Kiev: Naukova Dumka, 1980. Pp. 37-46. (in Russian).

8. Pylypenko V. V., Dolgopolov S. I. Experimental and calculated determination of dynamics equation coefficients for cavitation cavities in centrifugal-impeller pumps of different standard sizes. Teh. Meh. 1998. No. 8. Pp. 50-56. (in Russian).

9. Zadontsev V. A., Dolgopolov S. I., Grabovskaya T. A., Drozd V. A. Location effects of sensors for measuring frequency characteristics of cavitation pumps. Aviatsionno-Kosmicheskaya Tekhnika i Tekhnologia. 2007. No. 3(39). Pp. 85-90. (in Russian).

10. Pylypenko V. V., Dolgopolov S. I. Mathematical modelling RD-8 liquid rocket engine starting considering pumps cavitation. Teh. Meh. 2003. No. 2. Pp. 18-24. (in Russian).

11. Pilipenko V. V., Dovgot'ko N. I., Dolgopolov S. I., Nikolaev A. D., Serenko V. A., Khoryak N. V. Theoretical evaluation of the amplitudes of pogo vibrations in liquid propellant launch vehicles. Kosm. Nauka Tehnol. 1999. V. 5. No. 1. P. 90-96. (in Russian). https://doi.org/10.15407/knit1999.01.090

12. Pylypenko V. V., Dovgotko N. I., Nikolaev A. D., Dolgopolov S. I., Khoryak N. V., Serenko V. A. Theoretical determination of dynamic loads (longitudinal vibration accelerations) on design of RS-20 liquid missile at active flight trajectory. Teh. Meh. 2000. No 1. Pp. 3-18. (in Russian).

13. Chumak G. A. Calculations of starting acceleration of centrifugal-impeller pump considering cavitation. Cavitation Self-Oscillation and Dynamics of Hydraulic Systems. Kiev: Naukova Dumka, 1977. Pp. 84-89. (in Russian).

14. Zadontsev V. A. Experimental study of LR pump at cavitation autooscillations regimes. Proceedings of Third China-Russia-Ukraine Symposium on Astronautical Science and Technology, XI' AN China, September 16 - 20. 1994. Pp. 285-287.

15. Borovsky B. I., Ershov N. S., Ovsyannikov B. V., Petrov V. I., Chebaevsky V. F., Shapiro A. S. High-Speed Impeller Pumps. Moscow: Mashinostroyeniye, 1975. 336 pp. (in Russian).

DOI: https://doi.org/10.15407/itm2017.02.012

Copyright (©) 2017 S. I. Dolgopolov

Copyright © 2014-2018 Technical mechanics