We report results from a computational study of film cooling from cylindrical holes inclined at 35 degrees with respect to a flat surface using Large Eddy Simulations (LES). The hole length is L/d = 3.5, distance between the holes is P/d = 3, boundary layer above the flat surface is turbulent with Reθ = 938, density ratio = 0.95, velocity ratio = 0.5. All pertinent components of geometry, namel...

In order to cool the gas turbine vane or blade and raise operating temperature, two standard convective cooling methods are used: jet impingement film cooling. The current study uses computational analysis analyze compare effectiveness with without multi-jet on a flat plate. Ansys Fluent software is used perform results were compared experimental result using K-ω SST turbulence model validated ...

SUMMARY Experiments are reported in which film cooling tests are carried out using coolent injection through rows of discrete holes. A shock tunnel is used to provide a transient mainstream flow at stagnation temperatures of 5m°K, 1000°K and 2COO'K. Wall heat transfer rates are measured with and without coolant injection using thin film gauges. Mainstream Mach numbers of 0.2, 0.5 and 0.7 are em...

Effects that two different compound-angle film-hole configurations have on film cooling effectiveness are investigated. Effectiveness measurements have been made downstream of a single row of compound-angle cylindrical holes with a diameter of 7.5 mm, and a single row of compound-angle, diffuser-shaped holes with an inlet diameter of 7.5 mm. Both geometries were inclined with respect to the cov...

Graphene prepared on Cu foil by chemical vapor deposition was studied as a function of post growth cooling conditions. CuO islands embedded in the graphene film were discovered and studied by scanning electron microscopy, atomic force microscopy, and X-ray photoemission spectroscopy. It is shown that nanostructured holes can be formed within a graphene film by reduction using hydrogen cooling i...

In this paper, thin film based SiGe superlattice microrefrigerators are fabricated and characterized in terms of maximum cooling, power density and transient response. The localized cooling and fast transient response less than 40ps, demonstrate the potential for hot spot cooling of optoelectronics, microprocessor and IC chips.

Maximization of film-cooling effectiveness in an idealized film-cooling flow is accomplished using a gradientbased control strategy. The state equations are the two-dimensional unsteady incompressible Navier-Stokes equations along with the temperature equation. The control is a spatially and temporally varying normal velocity boundary condition subject to a constraint of zero mass and energy fl...

Numerical simulations of a three-dimensional model of impingement and film cooling on a flat plate are presented and validated with the available experimental data. Four different turbulence models were utilized for simulation, in which SST  had the highest precision, resulting in less than 4% maximum error in temperature estimation. A simplified geometry with periodic boundary conditions is de...

In film cooling heat transfer analysis, one of the core concepts is to deem film cooled adiabatic wall temperature (Taw) as the driving potential for the actual heat flux over the filmcooled surface. Theoretically, the concept of treating Taw as the driving temperature potential is drawn from compressible flow theory when viscous dissipation becomes the heat source near the wall and creates hig...