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ISSN Online: 2377-424X

International Heat Transfer Conference 12
August, 18-23, 2002, Grenoble, France

Heat/mass transfer coefficient for a single row of discrete injection holes - influence of hole orientation, shape and blowing rate

Get access (open in a dialog) DOI: 10.1615/IHTC12.1080
6 pages

Аннотация

The present work describes the detailed local mass/heat transfer coefficient distribution on a film-cooled plate with different hole geometries and blowing rates. The five geometries used for the injection holes include variations of two parameters: compound angle from 0° to 60° and uniform diameter injection hole or non-uniform (expansion or shaped) holes. The blowing rate is varied from 0.5 to 2.0.
For the mass transfer coefficient measurement, pure air is the injected flow (coolant). The heat transfer coefficient can be obtained from the mass transfer coefficient by the heat/mass transfer analogy. As the blowing rate increases, a large variation of the mass transfer coefficient in the lateral direction is observed near the injection holes. At blowing rates about 1.0, for compound angle injection an asymmetric vortex motion develops rapidly and induces asymmetric high mass transfer near the holes. The mass transfer coefficients are higher for compound angle injections with expansion than those for straight hole injection without compound angle at all blowing rates. However, the mass transfer coefficients for expansion hole injection without compound angle are similar to those for straight hole injection without compound angle at high blowing rate.