Convective heat transfer by a row of jets impinging on a concave surface

Abstract The attention of the present work is focused on the heat transfer between a concave surface and a row of air jets impinging on it. Measurements are performed with the heated thin foil heat transfer sensor using IR thermography as temperature transducer. Experimental tests are carried out by varying jets inclination, pitch, impinging distance, Mach and Reynolds numbers. Data is reduced in dimensionless form in terms of the Nusselt number and analyzed by separately accounting for the influence of the main relevant parameters. As main results, 3D Nusselt maps show presence of stream-wise vortices driven by surface curvature, jet inclination and jet pitch. At last, the Nusselt number, averaged over the impinged area, is represented as a function of the Reynolds number following a data correlation present in literature.

[1]  Walter H. Graf,et al.  Sediment erosion by Görtler vortices: the scour-hole problem , 2004, Journal of Fluid Mechanics.

[2]  S. Won,et al.  Technical Note The effect of concave surface curvature on heat transfer from a fully developed round impinging jet , 1999 .

[3]  Fulvio Scarano,et al.  Three-dimensional vortex dynamics and convective heat transfer in circular and chevron impinging jets , 2012 .

[4]  H Iacovides,et al.  Internal blade cooling: The Cinderella of computational and experimental fluid dynamics research in gas turbines , 2007 .

[5]  P. Mccormack,et al.  Taylor-Goertler Vortices and Their Effect on Heat Transfer , 1970 .

[6]  Gennaro Cardone,et al.  Heat transfer rate and uniformity in multichannel swirling impinging jets , 2012 .

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

[8]  B. Gebhart,et al.  Natural Convection Flows and Stability , 1973 .

[9]  V. J. Jusionis.  Heat transfer from impinging gas jets on an enclosed concave surface , 1970 .

[10]  Gennaro Cardone,et al.  Measurement of surface temperature and emissivity with stereo dual-wavelength IR thermography , 2010 .

[11]  Zeyuan Xu,et al.  Experimental Study of the Flow and Thermal Development of a Row of Cooling Jets Impinging on a Rotating Concave Surface , 2004 .

[12]  S. J. Kline,et al.  Describing Uncertainties in Single-Sample Experiments , 1953 .

[13]  S. Lee,et al.  A study of the heat transfer characteristics of turbulent round jet impinging on an inclined concave surface using liquid crystal transient method , 2007 .

[14]  Gennaro Cardone,et al.  Hypersonic Test Analysis by Means of Aerothermal Coupling Methodology and Infrared Thermography , 2013 .

[15]  Richard J Goldstein,et al.  Flow visualization of a round jet impinging on cylindrical surfaces , 1999 .

[16]  A. Ianiro,et al.  Temperature maps measurements on 3D surfaces with infrared thermography , 2012 .

[17]  Giovanni Maria Carlomagno,et al.  Infrared thermography for convective heat transfer measurements , 2010 .

[18]  Tommaso Astarita,et al.  Thermofluidynamic analysis of the flow in a sharp 180° turn channel , 2000 .

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

[20]  M. Fénot,et al.  An experimental study on hot round jets impinging a concave surface , 2008 .

[21]  Carosena Meola,et al.  A New Correlation of Nusselt Number for Impinging Jets , 2009 .

[22]  Goertler instability of wall jets , 1989 .

[23]  A. A. Tawfek,et al.  Heat transfer studies of the oblique impingement of round jets upon a curved surface , 2002 .

[24]  Giovanni Maria Carlomagno,et al.  Azimuthal instability in an impinging jet: adiabatic wall temperature distribution , 1995 .

[25]  Abdul A. Khan,et al.  Investigation of Flow through Orifices in Riser Pipes , 2010 .

[26]  Chie Gau,et al.  Surface Curvature Effect on Slot-Air-Jet Impingement Cooling Flow and Heat Transfer Process , 1991 .

[27]  P. Hrycak,et al.  Heat transfer from a row of impinging jets to concave cylindrical surfaces , 1981 .

[28]  D. E. Metzger,et al.  Local Heat Transfer in Internally Cooled Turbine Airfoil Leading Edge Regions: Part II—Impingement Cooling With Film Coolant Extraction , 1990 .

[29]  J.-M. Buchlin.  CONVECTIVE HEAT TRANSFER AND INFRARED THERMOGRAPHY (IRTH) , 2010 .