P. A. Baranov

Bio: P. A. Baranov is an academic researcher from Saint Petersburg State University. The author has contributed to research in topics: Vortex & Turbulence. The author has an hindex of 13, co-authored 60 publications receiving 519 citations. Previous affiliations of P. A. Baranov include Saint Petersburg State University of Civil Aviation & Saint Petersburg State Polytechnic University.

Identification of self-organized vortexlike structures in numerically simulated turbulent flow of a viscous incompressible liquid streaming around a well on a plane

Abstract: A system of Reynolds equations closed by adding a low-Reynolds-number Menter’s dissipative model of turbulence are solved with the use of a factorized finite-volume method. The generation of vortexlike structures in the case of stalled turbulent flow streaming around a deep well on a plane is analyzed. The effect of vortex intensification due to asymmetry of the well is discussed.

Correction of the Shear-Stress-Transfer Model with Account of the Curvature of Streamlines in Calculating Separated Flows of an Incompressible Viscous Fluid

Abstract: The necessity of correcting differential semiempirical turbulence models to calculate circulating flows of an incompressible viscous fluid is discussed. Approaches to taking account of the influence of the curvature of streamlines on turbulence characteristics are reviewed. Experience gained in modeling numerically two dimensional separated flows in a square and a cylindrical cavity on the wall of a plane-parallel channel is analyzed; an additional semiempirical constant in the expression for vortex viscosity of a modified shear-stress-transfer model is substantiated.

Simulating tornado-like enhancement of heat transfer under low-velocity motion of air in a rectangular dimpled channel. Part 2: Results of parametric studies

Abstract: Results from parametric studies on investigating enhancement of heat transfer by means of cavity-and ditch-shaped tornado-like intensifiers are presented.

Numerical Analysis of the Effect of Viscosity on the Vortex Dynamics in Laminar Separated Flow Past a Dimple on a Plane with Allowance for Its Asymmetry

Abstract: Based on numerical solution of the Navier–Stokes three‐dimensional stationary equations by a factorized finite‐volume method, the influence of physical viscosity on self‐organizing jet‐vortex structures in a dimple on a plane immersed in a laminar flow is analyzed with allowance for the asymmetry of the dimple shape.

Intensification of a Laminar Flow in a Narrow Microchannel with Single-Row Inclined Oval-Trench Dimples

Abstract: A fully developed laminar air flow in a plane-parallel channel of width 6 and height 1 with single-row inclined oval-trench dimples on the walls are calculated using multiblock computing technologies at Re = 103. A periodic channel section of length 4 with one dimple of length 4.5, width 1, an angle of inclination to the flow of 45°, and a depth varying from 0 to 0.375 is considered. Intensification of a laminar flow in the flow core in a channel supplied with trench dimples of depth more than 0.25, such that the maximum velocity is 1.5 times higher than the maximum flow velocity in a smooth channel, is found.

Comparison of Heat Transfer Augmentation Techniques

Abstract: Dr. Phil Ligrani is currently Professor of Mechanical Engineering and Director of the Convective Heat Transfer Laboratory at the University of Utah and a Fellow of the American Society of Mechanical Engineers. He has beenworking on convection heat transfer and fluid mechanics research problems since he received his Ph.D. degree from the Department of Mechanical Engineering at Stanford University in 1980. From 1979 to 1982, he was an Assistant Professor in the Turbomachinery Department of the von Karman Institute for Fluid Dynamics, Rhode-Saint-Genese, Belgium. From 1982 to 1984, he worked in the Department of Aeronautics of the Imperial College of Science and Technology, University of London. From 1984 to 1992, he was an Associate Professor in the Department of Mechanical Engineering of the U.S. Naval Postgraduate School. In his research, he has investigated the ultra-small-scale motions that exist near walls in turbulent boundary layers, the effects of surface roughness on turbulent boundary layers, transitional phenomena in curved channels including the development and structure of Dean vortex pairs, and innovative schemes for internal cooling and surface heat transfer augmentation, such as dimpled surfaces and swirl chambers, as well as a variety of gas turbine heat transfer and blade cooling problems. He served as Guest Editor for the journal Measurement Science and Technology from 1998 to 2000, and he will serve as Associate Technical Editor for the Journal of Heat Transfer from 2003 to 2006. He has published approximately 150 journal papers, conference papers, and book chapters. In 1995, he was presented with the "Professor of the Year" award at the University of Utah for outstanding classroom teaching. Some of his other activities and recognitions include a Guest Professorship in 2000 at the Institut fur Thermische Stroemungs-maschinen-Universitaet Karlsruhe, a Visiting Senior Research Fellowship from 1982 to 1983 at the Imperial College of Science and Technology-University of London, a NASA Space Act Tech Brief Award in 1991 for "Development of Subminiature Multi-Sensor Hot-Wire Probes," and the Carl E. and Jessie W. Menneken Faculty Award in 1990 for Excellence in Scientific Research. E-mail: ligrani@mech.utah.edu.

Free underexpanded jets in a quiescent medium: A review

Abstract: When dealing with high-pressure releases, be it needed by some operating conditions or due to an emergency protocol or even to the occurrence of an accident, one has to consider the relevant risks associated to this leakage. Indeed, in addition to the mechanical and blast effects, the dispersion of the released fluid is of primary importance if it is hazardous, as an example for toxic gases or flammable ones (where explosions or fires may be expected). In fact, despite the numerous studies dealing with underexpanded jets, many aspects of their structure are not clearly described, particularly when one seeks for quantitative predictions. By performing an exhaustive overview of the main experimental papers dealing with underexpanded jets, the present paper aims at clarifying the characteristics which are well known, from those where there is clearly a lack of confidence. Indeed, and curiously enough, such a work has never been done and no review is available on such a topic. Two particular regions have drawn most of the attention so far: the nearfield zone, where the shocks/rarefaction pattern that governs the structure of the jet is encountered, and the farfield zone, where the flow is fully developed and often approximated by an equivalent flow. Finally, some clues are given on the numerical methods that may be used if one wants to study such jets numerically, together with an emphasis on the specific thermodynamical difficulties associated to this kind of extreme conditions.

Heat Transfer Augmentation Technologies for Internal Cooling of Turbine Components of Gas Turbine Engines

Abstract: To provide an overview of the current state of the art of heat transfer augmentation schemes employed for internal cooling of turbine blades and components, results from an extensive literature review are presented with data from internal cooling channels, both with and without rotation. According to this survey, a very small number of existing investigations consider the use of combination devices for internal passage heat transfer augmentation. Examples are rib turbulators, pin fins, and dimples together, a combination of pin fins and dimples, and rib turbulators and pin fins in combination. The results of such studies are compared with data obtained prior to 2003 without rotation influences. Those data are comprised of heat transfer augmentation results for internal cooling channels, with rib turbulators, pin fins, dimpled surfaces, surfaces with protrusions, swirl chambers, or surface roughness. This comparison reveals that all of the new data, obtained since 2003, collect within the distribution of globally averaged data obtained from investigations conducted prior to 2003 (without rotation influences). The same conclusion in regard to data distributions is also reached in regard to globally averaged thermal performance parameters as they vary with friction factor ratio. These comparisons, made on the basis of such judgment criteria, lead to the conclusion that improvements in our ability to provide better spatially-averaged thermal protection have been minimal since 2003. When rotation is present, existing investigations provide little evidence of overall increases or decreases in overall thermal performance characteristics with rotation, at any value of rotation number, buoyancy parameter, density ratio, or Reynolds number. Comparisons between existing rotating channel experimental data and the results obtained prior to 2003, without rotation influences, also show that rotation has little effect on overall spatially-averaged thermal performance as a function of friction factor.

Influence of the Reynolds number and the spherical dimple depth on turbulent heat transfer and hydraulic loss in a narrow channel

Abstract: The paper presents detailed numerical study of heat transfer enhancement by a spherical dimple placed on a wall in a narrow channel. RANS approach with MSST model is applied to investigate the influence of the depth to diameter ratio Δ and the Reynolds number on the flow and heat transfer. Numerical model was successfully validated using LDV measurements, pressure loss data and LES results. Special attention is paid to identification of the flow topology at different Δ and Reynolds numbers. Contribution of different heat exchanger surface parts to the heat transfer enhancement is analyzed. Application of entropy production as a criterion of heat exchanger efficiency is discussed. Detailed information gained from the present computations can be used to get a deep insight into flow physics over dimpled surfaces and as a benchmark for validation of numerical and experimental methods.

Heat transfer—A review of 2005 literature

Abstract: The present review is intended to encompass the heat transfer literature published in 2005. While of a wide-range in scope, some selection is inevitable. We restrict ourselves to papers published in English through a peer-review process, with selected translations from journals published in other languages. Papers from conference proceedings generally are not included, though the Proceeding itself may be cited in the introduction. A significant fraction of the papers reviewed herein relates to the science of heat transfer, including experimental, analytical and numerical studies. Other papers cover applications where heat transfer plays a major role, not only in man-made devices but in natural systems as well. The papers are grouped into major subject areas and then into subfields within these areas. In addition to reviewing the literature, we mention major conferences held in 2005, major awards related to heat transfer presented in 2005, and books on heat transfer published during the year.