Shock Tube Study of the Effects of Large Density Differences and Blowing Ratio on Heat Transfer to a Film-Cooled Flat Plate.
Abstract
The effects of coolant-to-mainstream density ratio (D.R.) and mass flux (blowing) ratio (Mb) on flat plate heat transfer were investigated in a shock tube. The round-nosed plate has a single row of holes inclined 35 deg downstream with two-diameter lateral spacing and hole length of three diameters. Mixing helium with air in the shock tube produced a D.R. range of 1.2 to 2.1. The parameters studied approach those of film-cooled turbine components. For an Mb range of 0.4 to 3 and 10% mainstream turbulence, heat flux was measured with thin-film heat flux gauges located 4 to 30 hole diameters downstream of the cooling holes using an electrical analog. Various flow conditions were produced over the flat plate. The 'steady' portion of turbulent flow heat transfer data compared within 20% of the theoretical flat plate solution. Ratios of heat flux with cooling to heat flux without cooling versus M. and D.R. were determined. Analysis of the results showed film cooling heat transfer is correlated by coolant-to-mainstream velocity ratio. Effectiveness of cooling was reduced by the high mainstream turbulence.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 30, 1992
- Accession Number
- ADA258813
Entities
People
- Thomas A. Eads
Organizations
- Air Force Institute of Technology