A Combined Experimental and Numerical Characterization of the Flowfield and Heat Transfer around a Multiperforated Plate with Compound Angle Injection

Abstract

The aerodynamic and thermal behaviour of multiperforated zones in combustors is essential to the development of future combustion chambers. Detailed databases are therefore crucial for the validation of RANS/LES solvers, but also regarding the derivation of heat transfer correlations used in 0D/1D in-house codes developed by engine manufacturers. In the framework of FP7 EU SOPRANO Program, the test-rig used in a previous study is modified to be compatible with anisothermal conditions. The plate studied is a 12:1 model with a 90∘ compound angle injection. A heating system is used to generate a moderate temperature gradient of about 20 K between the secondary hot flow and the main cold flow. The aerodynamic field is acquired by a PIV 2D-3C (Stereo Particle Image Velocimetry) system. The surface heat transfer coefficient is derived based on surface temperature distribution acquisitions. Several heating power levels are tested, which allows evaluating the convective heat transfer coefficient and reference temperature through a linear regression. Measurements are conducted on both sides of the plate, which also gives access to those quantities on the injection/suction sides. From a numerical point of view, the configuration is studied using the unstructured ONERA in-house CEDRE solver with an advanced Reynolds Stress Model. A systematic comparison is presented between the experimental and numerical database. Due to the high blowing ratio, the film protection is low in the first rows, with a convective heat transfer coefficient enhancement around three, and freestream cold air brought close to the wall by vortices created at injection. After four rows, the film is building up, leading gradually to a better insulation of the wall. The comparison with the numerical simulation exhibits a qualitative agreement on the main flow structures. However, the mixing between the jets, the film and the freestream is underestimated by the calculation.

Heat and Flow Characteristics of Aerofoil-Shaped Fins on a Curved Target Surface in a Confined Channel for an Impinging Jet Array

“…The configuration of the impingement jets is essentially important due to the effect on heat transfer characteristics, and many researchers have investigated this subject. Different jet hole shapes [1][2][3][4], the arrangement of the jet holes [5][6][7][8], and the jet plate-target plate distances [3] were taken into account, and geometric optimization studies have been carried out in the literature. Additionally, Jung et al [1,9] compared the heat transfer characteristics of a standard and inclined jet array.…”

Enhancement of Film Cooling Effectiveness in a Supersonic Nozzle

“…Other benefits include skin friction reduction and energization of the boundary layer. In a recent study, consisting of experimental and numerical characterization of film cooling, Laroche et al [ 12 ] examined the impact of a high blowing ratio on cooling effectiveness—the thermal protection was found to be lower in the near field of the holes at higher values of the blowing ratio.…”

Research on the Hole Length Ratio of Fan-Shaped Holes in Flat Plate Film Cooling

“…Eberly and Thole, 2014 used timeresolved digital particle image velocimetry technology to measure the flow field of a row of cylindrical film cooling holes and found Kelvin-Helmholtz breakdown in the jet-tofreestream shear layer. Laroche et al, 2021 conducted research on film cooling of flat plates with a 90F0B0 compound angle and used the particle image velocimetry technique to document the velocity field. The temperature field was acquired using the cold wire technique.…”