numerical study has been carried out for slot air jet impingement cooling of horizontal concentric circular cylinders. the slot air jet is situated at the symmetry line of a horizontal cylinder along the gravity vector and impinges to the bottom of the outer cylinder which is designated as θ=0°. the outer cylinder is partially opened at the top with width of w=30mm and is kept at constant tempe...

It is found in many film-cooling experiments and computational analyses that a heated surface is employed to simulate the actual film-cooling condition with a cooling jet and a hot main flow. Considering that the dominant energy passage in turbine airfoil film cooling is always from the hot combustion gas flowing into the airfoil, employing a heated surface to simulate the actual film cooling c...

When manufacturing a turbine engine, the combustor annulus and are created as separate parts assembled. This leads to an inter-platform gap between two components, which must be supplied with leakage air prevent ingestion of extremely hot combustion gases into interior engine. The likely misalign because differential thermal expansion or assembly tolerances. paper presents direct numerical simu...

In film cooling experimental studies, due to the difficulty in measuring the surface heat flux variation, a Heat Flux Ratio (HFR) equation originally derived by Mick and Mayle [1], has been widely employed to calculate the surface heat flux distribution using the measured adiabatic film effectiveness and surface temperature. A close examination of the derivation process and applications of the ...

A new design concept is introduced to control the near-wall integration between the hot-gas boundary layer and the cooling jets in order to enhance the adiabatic film cooling effectiveness of the gas turbine blades. In this new approach, another film cooling port, having a very low blowing ratio, which prevents formation of the counter-rotating vortex pare, is applied just upstream of the main ...

The present paper reports the results of an experimental investigation influence coolant to mainstream density ratio (DR) on thermal and aerodynamic behavior a nozzle vane cascade with platform cooling through slot or discrete holes. Measurements were carried out 6 at low (1.6%) high (9%) inlet turbulence intensity level, blowing ratios (BR) varied in range 1-2. Tests performed injecting carbon...

In the present study, a hydrogen and oxygen heat-sink engine thrust chamber corresponding injection faceplate with discrete slot orifices are devised to study cooling performance near region. Moreover, set of experiments numerical simulations conducted evaluate effects various factors on combustion film efficiency. According obtained result, circumferential efficiency has an M-shaped distributi...

Aero gas turbine engines have been using mainly film cooling and convection cooling techniques. For operating at high gas temperature amongst different cooling options the transpiration cooling technique has emerged as the most promising technique to improve the gas turbine cycle performance by allowing higher turbine inlet temperatures. This paper investigates the advantages of transpiration c...

We investigate the properties of the modes supported by three-dimensional subwavelength plasmonic slot waveguides. We show that the fundamental mode supported by a symmetric plasmonic slot waveguide, composed of a subwavelength slot in a thin metallic film embedded in an infinite homogeneous dielectric, is always a bound mode. Its modal fields are highly confined over a wavelength range extendi...