Near-Wall Thermal Processes in an Inclined Impinging Jet: Analysis of Heat Transport and Entropy Generation Mechanisms

In this work, near-wall thermal transport processes and entropy generation mechanisms in a turbulent jet impinging on a 45 ∘ -inclined heated surface are investigated using a direct numerical simulation (DNS). The objectives are to analyze the subtle mechanisms of heat transport in the vicinity of an inclined impinged wall, to determine the causes of irreversibilities that are responsible for the reduction of performance of impingement cooling applications and to provide a comprehensive dataset for model development and validation. Results for near-wall thermal characteristics including heat fluxes are analyzed. An entropy production map is provided from the second law analysis. The following main outcomes can be drawn from this study: (1) the location of peak heat transfer occurs not directly at the stagnation point; instead, it is slightly shifted towards the compression side of the jet, while at this region, the heat is transported counter to the temperature gradient; (2) turbulent thermal and fluid flow transport processes around the stagnation point are considerably different from those found in other near-wall-dominated flows and are strongly non-equilibrium in nature; (3) heat fluxes appear highly anisotropic especially in the vicinity of the impinged wall; (4) in particular, the heated wall acts as a strong source of irreversibility for both entropy production related to viscous dissipation and to heat conduction. All these findings imply that a careful design of the impinged plate is particularly important in order to use energy in such a thermal arrangement effectively. Finally, this study confirms that the estimation of the turbulent part of the entropy production based on turbulence dissipation rates in non-reacting, non-isothermal fluid flows represents a reliable approximate approach within the second law analysis, likewise in the context of computationally less expensive simulation techniques like RANS and/or LES.

[1]  Paul G. Tucker,et al.  LES of Impingement Heat Transfer on a Concave Surface , 2010 .

[2]  B. L. Button,et al.  A review of heat transfer data for single circular jet impingement , 1992 .

[3]  Entropy generation and second law analysis of pulsed impinging jet , 2015 .

[4]  S. V. Prabhu,et al.  Experimental study and theoretical analysis of local heat transfer distribution between smooth flat surface and impinging air jet from a circular straight pipe nozzle , 2008 .

[5]  Shia-Hui Peng,et al.  On a Subgrid-Scale Heat Flux Model for Large Eddy Simulation of Turbulent Thermal Flow , 2002 .

[6]  Bassam A. Younis,et al.  A rational model for the turbulent scalar fluxes , 2005, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences.

[7]  Kai H. Luo,et al.  Unsteady heat transfer analysis of an impinging jet , 2002 .

[8]  Bernhard Weigand,et al.  MULTIPLE JET IMPINGEMENT − A REVIEW , 2009 .

[9]  S. Benhamadouche,et al.  Investigation of the interaction of a turbulent impinging jet and a heated, rotating disk , 2014 .

[10]  Kemal Hanjalic,et al.  Vortical structures and heat transfer in a round impinging jet , 2008, Journal of Fluid Mechanics.

[11]  P. Houwen.  Explicit Runge-Kutta formulas with increased stability boundaries , 1972 .

[12]  A. Sadiki.  Extended Thermodynamics as Modeling Tool of Turbulence in Fluid Flows , 2005 .

[13]  L. Brizzi,et al.  Experimental investigation of the flow and heat transfer of an impinging jet under acoustic excitation , 2011 .

[14]  M. Popovac,et al.  Large-eddy simulations of flow over a jet-impinged wall-mounted cube in a cross stream , 2007 .

[15]  James W. Baughn,et al.  Heat Transfer Measurements From a Surface With Uniform Heat Flux and an Impinging Jet , 1989 .

[16]  Yuichi Matsuo,et al.  DNS of turbulent heat transfer in channel flow with respect to Reynolds and Prandtl number effects , 1999 .

[17]  Salem Banooni,et al.  Investigation of heat transfer processes involved liquid impingement jets: a review , 2013 .

[18]  J. Sesterhenn,et al.  Statistics of fully turbulent impinging jets , 2016, Journal of Fluid Mechanics.

[19]  A. Mujumdar,et al.  Experimental study of formation and development of coherent vortical structures in pulsed turbulent impinging jet , 2016 .

[20]  S. Kim,et al.  The effect of inclination on impinging jets at small nozzle-to-plate spacing , 2012 .

[21]  L. Brizzi,et al.  Evidence of flow vortex signatures on wall fluctuating temperature using unsteady infrared thermography for an acoustically forced impinging jet , 2014 .

[22]  F. Beaubert,et al.  Large eddy simulations of plane turbulent impinging jets at moderate Reynolds numbers , 2003 .

[23]  Gongnan Xie,et al.  Gas Turbine Blade Tip Heat Transfer and Cooling: A Literature Survey , 2010 .

[24]  K Kiełczewski,et al.  Numerical study of the flow structure and heat transfer in rotating cavity with and without jet , 2013 .

[25]  Luc Vervisch,et al.  A compressible wall-adapting similarity mixed model for large-eddy simulation of the impinging round jet , 2009 .

[26]  Masud Behnia,et al.  Numerical study of turbulent heat transfer in confined and unconfined impinging jets , 1999 .

[27]  A. Dewan,et al.  Comparison of various integration to wall (ITW) RANS models for predicting turbulent slot jet impingement heat transfer , 2013 .

[28]  R. Viskanta.  Heat transfer to impinging isothermal gas and flame jets , 1993 .

[29]  D. Wen,et al.  Experimental study of curvature effects on jet impingement heat transfer on concave surfaces , 2017 .

[30]  H. Herwig,et al.  Local entropy production in turbulent shear flows: a high-Reynolds number model with wall functions , 2004 .

[31]  Laszlo Fuchs,et al.  LARGE EDDY SIMULATIONS OF A FORCED SEMICONFINED CIRCULAR IMPINGING JET , 1998 .

[32]  A. Dewan,et al.  Recent Trends in Computation of Turbulent Jet Impingement Heat Transfer , 2012 .

[33]  A. Bejan.  Entropy Generation Minimization: The Method of Thermodynamic Optimization of Finite-Size Systems and Finite-Time Processes , 1995 .

[34]  G. Batchelor.  Diffusion in a field of homogeneous turbulence , 1952, Mathematical Proceedings of the Cambridge Philosophical Society.

[35]  G. Lebon,et al.  Extended irreversible thermodynamics , 1993 .

[36]  A. Sadiki,et al.  Database of Near-Wall Turbulent Flow Properties of a Jet Impinging on a Solid Surface under Different Inclination Angles , 2018 .

[37]  Arun S. Mujumdar,et al.  Heat transfer and entropy generation in air jet impingement on a model rough surface , 2016 .

[38]  Ulrich Schumann.  THE COUNTERGRADIENT HEAT FLUX IN TURBULENT STRATIFIED FLOWS , 1987 .

[39]  Barry Koren,et al.  Quasi-DNS capabilities of OpenFOAM for different mesh types , 2014 .

[40]  E. Lamballais,et al.  Direct numerical simulation of a turbulent jet impinging on a heated wall , 2015, Journal of Fluid Mechanics.

[41]  C. Bogey,et al.  Large-eddy simulation of supersonic planar jets impinging on a flat plate at an angle of 60 to 90 degrees , 2015 .

[42]  A. Sadiki,et al.  Mixing Analysis and Optimization in Jet Mixer Systems by Means of Large Eddy Simulation , 2010 .

[43]  Francis H. Harlow,et al.  Transport Equations in Turbulence , 1970 .

[44]  XinGang Liang,et al.  Entransy—A physical quantity describing heat transfer ability , 2007 .

[45]  Bahram Moshfegh,et al.  Large-eddy simulation of an impinging jet in a cross-flow on a heated wall-mounted cube , 2009 .

[46]  J. Lumley,et al.  Turbulence measurements in axisymmetric jets of air and helium. Part 1. Air jet , 1993, Journal of Fluid Mechanics.

[47]  N. Saniei,et al.  Heat Transfer From an Obliquely Impinging Circular Air Jet to a Flat Plate , 1996, Heat Transfer: Volume 2 — Heat Transfer in Turbulent Flows; Fundamentals of Convection Heat Transfer; Fundamentals of Natural Convection in Laminar and Turbulent Flows; Natural Circulation.

[48]  Kui Soon Kim.  An experimental study on the flow and heat transfer characteristics of an impinging jet , 1993 .

[49]  P. Hrycak,et al.  Heat transfer from round impinging jets to a flat plate , 1983 .

[50]  S. V. Prabhu,et al.  Influence of the shape of the orifice on the local heat transfer distribution between smooth flat surface and impinging incompressible air jet , 2016 .

[51]  Bernhard Weigand,et al.  Multiple Jet Impingement − A Review , 2011 .

[52]  Gautam Biswas,et al.  Large-eddy simulation of flow and heat transfer in an impinging slot jet , 2001 .

[53]  Toshitake Ando,et al.  Direct Numerical Simulation of Active-Controlled Impinging Jets , 2009 .

[54]  Hirofumi Hattori,et al.  Direct Numerical Simulation of Turbulent Heat Transfer in Plane Impinging Jet , 2004 .

[55]  K. Hanjalic,et al.  Wall imprint of turbulent structures and heat transfer in multiple impinging jet arrays , 2005, Journal of Fluid Mechanics.

[56]  Richard J Goldstein,et al.  Heat transfer from a flat surface to an oblique impinging jet , 1988 .

[57]  Adrian Bejan,et al.  Second-Law Analysis in Heat Transfer and Thermal Design , 1982 .

[58]  Yongmann M. Chung,et al.  Large-eddy simulations of a turbulent jet impinging on a vibrating heated wall , 2017 .

[59]  B. Weigand,et al.  LES simulations of an impinging jet: On the origin of the second peak in the Nusselt number distribution , 2013 .

[60]  Suresh V. Garimella,et al.  Effects of nozzle-inlet chamfering on pressure drop and heat transfer in confined air jet impingement , 2000 .

[61]  M. Fénot,et al.  The effect of nozzle geometry on local convective heat transfer to unconfined impinging air jets , 2016 .

[62]  Bekir Sami Yilbas,et al.  Local entropy generation in an impinging jet: minimum entropy concept evaluating various turbulence models , 2001 .

[63]  P. R. Voke,et al.  Numerical study of heat transfer from an impinging jet , 1998 .

[64]  K. Tsujimoto,et al.  DNS analysis of multiple impinging jets , 2014 .

[65]  Jungho Lee,et al.  The effect of nozzle configuration on stagnation region heat transfer enhancement of axisymmetric jet impingement , 2000 .

[66]  A. Sadiki,et al.  On Thermodynamics of Turbulence: Development of First Order Closure Models and Critical Evaluation of Existing Models , 2000 .

[67]  P. Roe.  CHARACTERISTIC-BASED SCHEMES FOR THE EULER EQUATIONS , 1986 .

[68]  G. Ahmadi.  A Two-Equation Turbulence Model for Compressible Flows Based on the Second Law of Thermodynamics , 1989 .

[69]  Johannes Janicka,et al.  Thermal Transport and Entropy Production Mechanisms in a Turbulent Round Jet at Supercritical Thermodynamic Conditions , 2017, Entropy.

[70]  B. Niceno,et al.  Large Eddy Simulation of multiple impinging jets in hexagonal configuration - Flow dynamics and heat transfer characteristics , 2017 .

[71]  A. Chorin.  Numerical Solution of the Navier-Stokes Equations* , 1989 .

[72]  Darina B. Murray,et al.  Fluctuating fluid flow and heat transfer of an obliquely impinging air jet , 2008 .

[73]  Florent Duchaine,et al.  Investigation of the concave curvature effect for an impinging jet flow , 2017 .

[74]  H. Deniau,et al.  Large-Eddy simulation of an impinging heated jet for a small nozzle-to-plate distance and high Reynolds number , 2017 .

[75]  N. Lior,et al.  Impingement Heat Transfer: Correlations and Numerical Modeling , 2005 .

[76]  Y. Akansu,et al.  Flow field and heat transfer characteristics in an oblique slot jet impinging on a flat plate , 2008 .

[77]  Impingement cooling from a circular jet in a cross flow , 1975 .

[78]  Yu-Chao Hua,et al.  Irreversibility and Action of the Heat Conduction Process , 2018, Entropy.

[79]  M. Bovo,et al.  Single pulse jet impingement on inclined surface, heat transfer and flow field , 2013 .

[80]  J. Lienhard,et al.  Wall Roughness Effects on Stagnation-Point Heat Transfer Beneath an Impinging Liquid Jet , 1994 .

[81]  Noam Lior,et al.  Jet Impingement Heat Transfer: Physics, Correlations, and Numerical Modeling , 2006 .

[82]  A. Gorobets,et al.  DNS and RANS modelling of a turbulent plane impinging jet , 2012 .

[83]  C. Beguier,et al.  Ratio of scalar and velocity dissipation time scales in shear flow turbulence , 1978 .

[84]  Sunil Chandel,et al.  Influence of jet temperature and nozzle shape on the heat transfer distribution between a smooth plate and impinging air jets , 2016 .

[85]  Shin-ichi Satake,et al.  Direct numerical simulation of an impinging jet into parallel disks , 1998 .

[86]  S. V. Prabhu,et al.  Influence of the shape of the nozzle on local heat transfer distribution between smooth flat surface and impinging air jet , 2008 .

[87]  F. Duchaine,et al.  Secondary peak in the Nusselt number distribution of impinging jet flows: A phenomenological analysis , 2016 .

[88]  H. Martin.  Heat and Mass Transfer between Impinging Gas Jets and Solid Surfaces , 1977 .