Effect of Vortex Circulation on Injectant from a Single Film-Cooling Hole and a Row of Film-Cooling Holes in a Turbulent Boundary Layer. Part 2. Injection Beneath the Vortex Upwash
Abstract
Results are presented which illustrate the effects of single embedded longitudinal vortices on heat transfer and injectant downstream of a row of film-cooling holes and downstream of a single hole in a turbulent boundary layer. Changes resulting as circulation magnitudes of the vortices are varied from 0.0 to 0.144 sq m/s. Mean temperature results are presented which show how the injectant is distorted and redistributed by vortices, along with heat transfer measurements and mean velocity surveys. Injection hole diameter is 0. 952 cm to give a ratio of vortex core diameter to hole diameter of about 1.5-1. 6. Freestream velocity is maintained at 10 m/s, and the blowing ratio is approximately 0.5. Film-cooling holes are oriented 30 deg with respect to the test surface. Stanton numbers are measured on a constant heat flux surface with a nondimensional temperature parameter of about 1.5. The situation studied is one where the middle injection hole is beneath the vortex upwash. For all results, vortex centers pass well within 2.9 vortex core diameters of the middle injection hole. To quantify influences of the vortices on the injectant, the parameter S is introduced, defined as the ratio of vortex circulation to injection hole diameter times mean injection velocity. The perturbation to film injectant and local heat transfer is determined by the magnitude of S. When S is > 1.0-1.5, injectant is swept into the vortex upwash and above the vortex core by secondary flows, and Stanton number data show little evidence of injectant beneath the vortex core and downwash near the wall. Theses.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1989
- Accession Number
- ADA223894
Entities
People
- Pisut Kaisuwan
Organizations
- Naval Postgraduate School