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

English
Russian
Ukrainian
Home > Journal Issues > ¹ 2 (2015) Technical mechanics > 10
___________________________________________________

UDC 681.3:06/519.245+533.7

Technical mechanics, 2015, 2, 100 - 109

NUMERICAL STUDIES OF PARALLELING TEST PARTICLES METHOD USING STATISTIC INDEPENDENT TESTS

L. L. Pecheritsa

'
      ABSTRACT

      The test particles method (TPM) as a version of the Monte-Carlo statistic method for the stationary state- ment is considered. Nonparalleling a sequential algorithm of the TPM as large independent subproblems (LISs) has been performed at previous stages. Testing the LISs algorithm using the problem of an internal flow through Laval nozzle followed by the environmental spraying jet has demonstrated a high degree of the efficiency and the algorithm acceleration. However, testing with a problem of an internal flow past has revealed LISs significant disadvantages. It has been found that the algorithm developed has violated in fact some TPM principles resulting in poorly determined velocity fields in the course of iterations. A demand arose for construction of a parallel algorithm to accelerate the determination of velocity fields. Thus, the algorithm for paralleling on statistically inde- pendent tests (PSIT) has been developed to take into account velocity disturbances in simulating trajectories of test particles on each operational cores in a single formable field. PSIT reduces to a series of parallel tests con- ducted singly on each core. Following computations, the data are synchronized between cores, namely, an ex- change of accumulated variations in velocity disturbances of field molecules. Subsequent drawing trajectories on all of the cores is conducted on a single renewed velocity field. After all of the tests the summary characteristics due to computational meshes are transferred to one of cores where moments of the disturbance function are aver- aged on the summing time of residence of particles into meshes. Using the PSIT algorithm, test computations are made using a multi-core processor. The results obtained are compared with the analogue data of the TPM sequential algorithm, as well as the one-core computational results. It is established that the number of cores used is not affected the results obtained and affected only the estimated time when using the PSIT. The time for various ver- sions of the PSIT updated algorithm to minimize the estimated time due to reduction of the number of exchanges between cores is fully considered in the paper. Pdf (English)







      KEYWORDS

Monte-Carlo method, test particles method, parallel algorithms, multi-core computer, estimated time.

      FULL TEXT:

Pdf (English)









      REFERENCES

1. Bird G. Molecular Gas Dynamics (in Russian) / G. Bird. – Moscow : Mir, 1981. – 319 p.

2. Vlasov V. I. Improvement in statistic tests method (Monte-Carlo) for calculations of flows of rarified gases (in Russian) / V. I. Vlasov // Doklady AN SSSR. – 1966. – Vol. 167, No 5. – Ð. 1016 – 1018.

3. Vlasov V. I. Conservative version of test molecules method (Monte-Carlo) (in Russian) / V. I. Vlasov // Pro- ceedings of 8th All-Union Conference on Dynamics of Rarified Gases (Numerical and Analytical Methods for Dynamics of Rarified Gases). – Moscow, 1986. – P. 81 – 85.

4. Voevodin V. V. Paralleling for algorithms and programs (in Russian) / V. V. Voevodin // Computational Proc- esses and Systems / Edited by G. I. Margun. – Moscow : Nauka, 1993. – Vol. 10. – p. 253 – 270.

5. Bykov N. Yu. Realization of high-efficient estimated algorithms for programs of a direct statistic simulation in problems of rarified gas dynamics (in Russian) / N. Yu. Bykov, L. Yu. Nikolaeva // Parallel Computational Technologies (PaVT2008): Proceedings of International Scientific Conference. – Chelyabinsk : Publishing House of YuUrGU, 2008. – P. 314 – 317.

6. Bykov N. Yu. Parallel Direct Monte-Carlo Simulation of Non-Steady Flows of Rarified Gas Using Parallel- Massive Supercomputers for Molecular Gas Dynamics (in Russian) / N. Yu. Bykov, G. A. Lukyanov. – St- Petersburg, 1997. – 33 p. (Preprint/ Institute of High-Efficient Computations and Data Bases; No 5-97).

7. Grishin I. A. Paralleling with Data of Direct Monte-Carlo Simulation for Molecular Gas Dynamics (in Russian) / I. A. Grishin, V. V. Zakharov, G. A. Lukyanov. – St-Petersburg, 1998. – 32 p. (Preprint/ Institute of High- Efficient Computations and Data Bases: No 03-98).

8. Zakharov V. V. Parallel Algorithms of Direct Monte-Carlo Simulation for Molecular Gas Dynamics: Methodic Guidelines for Users (in Russian) / V. V. Zakharov, G. A. Lukyanov, G. O. Khanlarov. – St-Petersburg : Institute Of High-Efficient Computations and Data Bases, 1999. – 46 p.

9. Algorithms of two-level paralleling PC for non-steady problems of molecular gas dynamics (in Russian) /A. V. Bogdanov, N. Yu. Bykov, I. A. Grishin, V. V. Zakharov, G. A. Lukyanov, G. O. Khanlarov // Mate- maticheskoe Modelirovanie. – 2000. – Vol. 12, No 6. – P. 97 – 101.

10. Zakharov V. V. Parallel direct Monte-Carlo simulation of flows of rarified gas on multi-processor computational systems of various architecture (in Russian) / V. V. Zakharov, G. A. Lukyanov // Paper Abstracts for 3rd All-Russian Youth School on Supercomputer Computational and Information Technologies for Physical and Chemical Studies, Chernogolovka, 2001. – P. 42 – 46.

11. Supercomputer technologies for direct Monte-Carlo simulation for Molecular gas Dynamics http://www.umlab.ru/

12. Pecheritsa L. L. Parallel algorithm of test particles method for problems of molecular gas dynamics (in Russian) / L. L. Pecheritsa // Tekhnicheskaya Mekhanika. – 2013. – No 1. – P. 32 – 44.

13. Pecheritsa L. L. Construction of optimal algorithms for test particles method of rarified gases dynamics (in Russian) / L. L. Pecheritsa, T. G. Smelaya, N. V. Petrushenko // Modern Problems of Rarified Gases Dynamics: Proceedings of 4th All-Russian Conference (26 – 29 July, 2013) – Novosibirsk. – P. 164 – 166.

14. Grishin I. A. Paralleling with Direct Monte-Carlo Simulation for Molecular Gas Dynamics (in Russian) / I. A. Grishin, V. V. Zakharov, G. A. Lukyanov. – St-Petersburg, 1998. – 32 p. (Preprint/ Institute of High- Efficient Computations and Data Bases: No 03-98).

15. Aerogasdynamic Support for Space Projects (in Russian) / M. G. Abramovskaya, V. P. Bass, N. V. Petrushenko, L. L. Pecheritsa // Kosmichni Doslidzhennya v Ukraini 2004 – 2006. – Kyiv : IKD NANU- NKAU, 2006. – P. 78 – 86.

16. Pecheritsa L. L. Special features of parallel algorithm of statistically independent tests of method of test particles (in Russian) / L. L. Pecheritsa // Kosmichni Doslidzhennya v Ukraini 2014: Proceedings. – Kyiv : IKD NANU-NKAU, 2014. – P. 122.

17. Bass V. P. Numerical solution of 3D problems in dynamics of rarified gas (in Russian) / V. P. Bass, L. L. Pecheritsa // Tekhnicheskaya Mekhanika. – 2010. – No 2. – P. 38 – 51.

18. Alekseeva Ye. V. Local Method of Aerodynamic Calculations for Rarified Gas (in Russian) / Ye. V. Alekseeva, R. G. Barantsev. – Leningrad : LGU, 1976. – 210 p





Copyright (©) 2015 L. L. Pecheritsa

Copyright © 2014-2018 Technical mechanics


____________________________________________________________________________________________________________________________
GUIDE
FOR AUTHORS
Guide for Authors