Heat transfer from roughened surfaces using interferometry
Abstract
Holographic interferometry is used to study the thermal fields over numerous twodimensional ribbed geometry and to ascertain the Nusselt number distribution around them. Full field information is provided as the fringe pattern generated is essentially an isotherm contour map of the flow situation. Hence, this makes it ideally suited to verify the theoretical solutions obtained from Large Eddy Simulations (LES) and Finite Element predictions. Initially, a smooth surface geometry was investigated to verify the accuracy of the experimental technique. Ribbed geometries with a pitch to height ratio of 7.2:1 were then studied. Double exposure and realtime techniques enabled both detailed thermal measurements to be made and any timedependency of the field to be identified. Flow rates up to nuclear reactor conditions were studied and typical interferograms are illustrated. Numerical simulations of the flow were taken using the Kepsilon and qf models employed in the finite element code FEAT. Incorrect modelling of the length scles in the near wall region using a low Reynolds number model led to errors in the thermal field predictions. Hence, only a qualitative comparison with the experimental results is undertaken.
 Publication:

Ph.D. Thesis
 Pub Date:
 1987
 Bibcode:
 1987PhDT........49L
 Keywords:

 Finite Element Method;
 Heat Transfer;
 KEpsilon Turbulence Model;
 Surface Reactions;
 Surface Roughness;
 Temperature Distribution;
 Computer Programs;
 Diffraction Patterns;
 Holographic Interferometry;
 Laser Interferometry;
 Nusselt Number;
 Prediction Analysis Techniques;
 Fluid Mechanics and Heat Transfer