Position: Professor

Department: Mathematical modelling and numerical simukations

Room number: 404

Phone: +359 2 979 6463

E-mail: stefanov@imbm.bas.bg

stefanov@mech.bas.bg

 

Scientific degrees, institution, year:

 

 

 

Engineer - physicist, Kharkov Polytechnic Institute, USSR, 1975.

Specialization: Applied Mathematics, Sofia Polytechnic University, 1977

Ph.D., Fluid Mechanics, Sofia University, 1987

D.Sc., Institute of Mechanics, BAS, 2011

Fields of Research:

Kinetic theory, Rarefied gas dynamics, Microfluidics, Monte Carlo methods, Fluid Mechanics, Numerical methods

Extended Information

    Recent Publications:

  1. S. Stefanov, C. Cercignani, “Monte Carlo Simulation of Benard's Instability in a Rarefied Gas”, European Journal of Mechanics, B/Fluids, vol.11, No 5, pp. 543-554, 1992.

  2. C.Cercignani, S. Stefanov, “Benard's Instability in Kinetic Theory; Transport Theory and Statistical Physics, Marcell Dekker Inc. vol.21, No. 4-6, pp.371-381, 1992.

  3. S.Stefanov, C. Cercignani, “Monte Carlo Simulation of the Taylor-Couette Flow of a Rarefied Gas”, Journal of Fluid Mechanics, vol.256, pp.199-213, 1993.

  4. G.Gorelik, N.Pavljukevic, S.Radev, S.Stefanov, S.Zalenskiy, “Kinetics of Mass transfer through Porous Medium for Strong Evaporation”, Int.J. of Heat and Mass Transfer, vol.36, pp.3369-3374, 1993.

  5. S.Stefanov, C. Cercignani, “Monte Carlo Simulation of a Channel Flow of a Rarefied Gas”, European Journal of Mechanics, B/Fluids, vol.13, No 1,pp.93-114, 1994.

  6. S.Stefanov; “Monte Carlo Simulation of molecular beams in a Hot-Wall Epitaxy System”, Vacuum, Pergamonn Press, vol.45, No 8, pp.857-865, 1994.

  7. Frezzotti and S. Stefanov ; “DSMC Analysis of the Evaporation of Iodine between Parallel Plates”, Proc.of 19-th. Intern.RGD Symp., J.Harley and G.Lord edts, Oxford Science Publications, Oxford, UK, Vol.1, pp.298-304, 1995.

  8. Cercignani and S. Stefanov , “Vortices and Turbulence in Hypersonic Rarefied Flows”; Proc.of 19-th. Intern.RGD Symp., J.Harley and G.Lord edts., Oxford Science Publications, Oxford,UK,Vol.2, pp.1147-1153, 1995.

  9. M. Ota and S. Stefanov, “Monte Carlo Simulation of a Low Pressure Chemical Vapour Deposition Flow”; Proc.of 20-th. Intern.RGD Symp., edt. C. Shen, Peking University Press,pp. 625-629, 1997.

  10. S. Stefanov and C. Cercignani, “Monte Carlo Simulation of the Propagation of a Disturbance in the Channel Flow of a Rarefied Gas”, Special issue "Simulation methods in Kinetic Theory" of Computers and Mathematics with Applications, Vol. 35, No 1-2, pp. 41-53, 1998.

  11. S. Stefanov, P.Gospodinov and C.Cercignani, “Monte Carlo Simulation and Navier-Stokes Finite Differnce Solution of Rarefied Gas Flow Problems”, Physics of Fluids, Vol. 10, No 1, pp. 289-300, 1998.

  12. S.Stefanov, A. Frezzotti, V. Levdansky, V. Leitsina, N. Pavljukevich, “Direct Statistical Simulation of Gas Mixture Mass Transfer in a Porous Layer with Condensation of One of the Components and Absorption of Another”, Int. J. of Heat and Mass Transfer, vol.42, pp. 2063-2069, 1999.

  13. V. Roussinov, S. Stefanov, V. Yanitskii, “Chaotic Spatiotemporal Structures in the Rayleigh-Benard flow of a Rarefied gas”, Theoretical and Applied Mechanics, Sofia, vol. 30, No. 1 pp. 29-38, 2000.

  14. S. Stefanov, I. Boyd, C. Cai, “Monte Carlo analysis of macroscopic fluctuations in a rarefied hypersonic flow around a cylinder”, Physics of Fluids, vol. 12, No. 5, pp. 1226-1239, 2000.

  15. S. Stefanov, V. Roussinov, C. Cercignani, “Rayleigh-Benard flow of a rarefied gas and its attractors. Part 1: Convection regime”, Physics of Fluids, Vol. 14, No 7, pp. 2255-2269, 2002.

  16. S. Stefanov, V. Roussinov, C. Cercignani, “Rayleigh-Benard flow of a rarefied gas and its attractors. Part 2: Chaotic and periodic convective regimes”, Physics of Fluids, Vol. 14, No 7, pp. 2270-2288, 2002.

  17. S. Stefanov, “Direct Monte Carlo simulation of gas flows through highly porous media”, In: “Current issues on heat and mass transfer in porous media”, Proceedings of NATO Advance Study Institute, edt. D. Ingham, Published by Ovidius University press, pp. 520-528, 2003

  18. M.Ota, K. Kuwahara, S. Stefanov, “Motion of a spherical aerosol particle in a micro-pipe”, "Rarefied Gas Dynamics", 23rd Int. Symp., A.D. Ketsdever and E.P.Muntz Eds., AIP Conf. Proc. 663, American Institute of Physics, New York, pp. 776-783, 2003.

  19. S. Stefanov, V. Roussinov and C. Cercignani, “The Attractors of the Rayleigh-Benard Flow of a Rarefied Gas", in "Rarefied Gas Dynamics", 23rd Int. Symp., A.D. Ketsdever and E.P.Muntz Eds., AIP Conf. Proc. 663, American Institute of Physics, New York, pp. 194-201, 2003.

  20. S.K. Stefanov, R.W. Barber, M. Ota and D.R. Emerson,” Comparison between Navier-Stokes and DSMC Calculations for Low Reynolds Number Slip Flow Past a Confined Microsphere”, in "Rarefied Gas Dynamics", 24rd Int. Symp., 2004 (in print).

  21. S. K. Stefanov, R. W. Barber, M. Ota, and D. R. Emerson, “Comparison between Navier-Stokes and DSMC Calculations for Low Reynolds Number Slip Flow Past a Confined Microsphere”, RGD24 Int. Symp., Ed. Mario Capitelli, AIP Conference proceeding, 762, American Institute of Physics, pp. 701-706, 2005.

  22. Ying He, M. Ota, and S. K. Stefanov, “Carbon Deposition on Blade Surfaces of Laser Microactuator for Optical MEMS”, RGD24 Int. Symp., Ed. Mario Capitelli, AIP Conference proceeding, 762, American Institute of Physics, pp. 737-742, 2005.

  23. S. K. Stefanov, V. M. Roussinov, and C. Cercignani, “Three-Dimensional Rayleigh-Bénard Convection of a Rarefied Gas: DSMC and Navier-Stokes Calculations”, RGD24 Int. Symp., Ed. Mario Capitelli, AIP Conference proceeding, 762, American Institute of Physics, pp. 529-534, 2005.

  24. S. K. Stefanov, R. W. Barber, D. R. Emerson, , and J. M. Reese,"The Critical Accommodation Coefficient for Velocity Inversion in Rarefied Cylindrical Couette Flow in the Slip and Near Free-Molecular Regimes", In Proc. RGD25 Int. Symp., Eds. A.K. Rebrov and M.S. Ivanov, Publishing House Siberian Branch RAS, pp. 1134-1139 (2007).

  25. K. S. Shterev and S. K. Stefanov, "Two-dimensional Slip-Velocity Gaseous Flow past a Confined Square in a Microchannel", In Proc. RGD25 Int. Symp., Eds. A.K. Rebrov and M.S. Ivanov, Publishing House Siberian Branch RAS, pp. 1182-1187(2007).

  26. Masahiro Ota, He Ying, and S. K. Stefanov, “Monte Carlo Simulation Of Rotation Of A Laser Opto-Microactuator”, In Proc. RGD25 Int. Symp., Eds. A.K. Rebrov and M.S. Ivanov, Publishing House Siberian Branch RAS, pp. 1134-1139 (2007).

  27. S. Mizzi, R. W. Barber, D. R. Emerson, J. M. Reese, and S. K. Stefanov, “A Phenomenological and Extended Continuum Approach for Modeling Non-equilibrium Flows”, Continuum Mech. Thermodyn., 19, pp. 273-283 (2007).

  28. S. Mizzi, D. R. Emerson, S. K. Stefanov, R. W. Barber, and J. M. Reese, “Effects of Rarefaction on Cavity Flow in the Slip Regime”, J. Comput.. Theoret. Nanoscience, 4, No. 4, pp. 817-822 (2007).

  29. D. R. Emerson, X. J. Gu, S. K. Stefanov, S. Yuhong, and R. W. Barber, “Nonplanar Oscillatory Shear Flow: From the Continuum to the Free-molecular regime”, Physics of Fluids, 19, 107105 (2007).

  30. S. Stefanov, V. Roussinov, and C. Cercignani, “Rayleigh-Benard Flow of a Rarefied Gas and its Attractors. III. Three-dimensional Computer Simulations”, Physics of Fluids, 19, 124101 (2007).

  31. Ying HE, M. OTA, S. K. Stefanov,  Effects of carbon fiber pressure, temperature and deposition distance on thermo fluids phenomena in vacuum deposition machine, Journal of Thermal Science, 17, No 3, pp. 253-260 (2008). IF 0.212

  32. S. K. Stefanov, A DSMC algorithm for gaseous flows through rough microchannels, CD Proceedings of the 1st GASMEMS Workshop- Eindhoven, September 9-11, 2009, GASMEMS09-07, 2010, www.gasmems.eu.

  33. K. S. Shterev, S. K. Stefanov, Pressure based finite volume method for calculation of compressible viscous gas flows, Journal of Computational Physics, 229, 461–480 (2010), ISSN 0021-9991, IF 3.023

  34. K.S.  Shterev, S. K. Stefanov, A Parallelization of finite volume method for calculation of gas microflows by domain decomposition methods , Lecture Notes in Computer Science , LARGE-SCALE SCIENTIFIC COMPUTING, Springer, Volume: 5910 Pages: 523-530, 2010, ISSN 0302-9743 (Print) 1611-3349 (Online), ISBN 978-3-642-12534-8. SJR 0.322

  35. S.K.Stefanov, Particle Monte Carlo algorithms with small number of particles in grid cells, in: Numerical Methods and Applications, Lecture Notes in Computer Science, Springer, Volume 6046, pp. 110-117, 2011. SJR 0.322

  36. S. K. Stefanov, On DSMC calculations of rarefied gas flows with small number of particles in cells, SIAM Journal on Scientific Computing, Society for Industrial and Applied Mathematics, Vol. 33, No. 2, pp. 677–702, 2011. IF 3.016

  37. P. Gospodinov, V. Roussinov, S. Stefanov, Nonisothermal oscillatory cylindrical Couette gas flow in the slip regime: A computational study, European Journal of Mechanics - B/Fluids, Volume 33, May–June 2012, Pages 14–24. IF 1.476

  38. H. Akhlaghi, E. Roohi, S. Stefanov.  A new iterative wall heat flux specifying technique in DSMC for heating/cooling simulations of MEMS/NEMS, (2012) International Journal of Thermal Sciences, 59, pp. 111-125. IF 0.322.

  39. A. Dinler, R. W. Barber, D. R. Emerson, S. K. Stefanov, K. Orucoglu. Role of surface shape on boundary slip and velocity defect, (2012) Physical Review E - Statistical, Nonlinear, and Soft Matter Physics, 86 (1), art. no. 016314. IF 2.313

  40. A. Mohammadzadeh, E. Roohi, H. Niazmand,S. Stefanov, R. S. Myong, Thermal and second-law analysis of a micro- or nanocavity using direct-simulation Monte Carlo, (2012) Physical Review E - Statistical, Nonlinear, and Soft Matter Physics, 85 (5), art. no. 056310. IF 2.313

  41. S. Stefanov, DSMC Collision Algorithms Based on Kac Stochastic Model, AIP Conf. Proc. 1501, 609-615 (2012); doi: 10.1063/1.4769598, ISBN: 978-0-7354-1115-9. SJR 0.139

  42. M. Vargas, S. Stefanov, and V. Roussinov, Transient heat transfer flow through a binary gaseous mixture confined between coaxial cylinders. International Journal of Heat and Mass Transfer, 59: p. 302-315, 2013. IF 2.598

  43. N. Dongari, R. W. Barber, D. R. Emerson, S. K. Stefanov, Y. H. Zhang and J. M. Reese, The effect of Knudsen layers on rarefied cylindrical Couette gas flows, Microfluidics and Nanofluidics, 14 (2013), pp. 31-43. IF 3. 447

  44. A. Dinler, R. W. Barber, D. R. Emerson, S. K. Stefanov, K. Orucoglu, On the degree of boundary slip over nonplanar surfaces, Microfluid Nanofluid, Vol. 15, Issue 6, December 2013, pp. 807-816р 2013, DOI 10.1007/s10404-013-1183-z. IF 3.447

  45. A. Amiri-Jaghargh, E. Roohi, H. Niazmand, S. Stefanov: DSMC Simulation of Low Knudsen Micro/Nanoflows Using Small Number of Particles per Cells. J Heat Trans-T Asme 135(10) (2013). IF 1.762

  46. A. Dinler, R. W. Barber, D. R. Emerson, S. K. Stefanov, K. Orucoglu: The Effects of the S-Layer on Nonplanar Microflows: A Critical View on the Accuracy of Slip Models. J Comput Theor Nanos 10(9), 1990-1998 (2013). IF 0.673

 

Recent Projects:

ММ1404/2004 : Mathematical modeling of viscous gas microflows;

Marie Curie Initial Training Programme (Seventh Framework Programme , SP3-People):

GRANT GASMEMS: Gas Flows in Micro Electro Mechanical System

PITN-GA-2008-215504