A global noise reduction of a high-subsonic jet is achieved by experimental use of an impinging microjets system. The microjet velocity relative to the main jet velocity, the longitudinal distance of injection and the number of microjets are the three parameters examined in order to obtain the maximum noise reduction. This optimized microjet configuration is obtained by a balance between low-fr...

The increasing use of high-pressure water jets in the industry for machining materials yields numerous studies aiming at the optimization of this technology. Since the experimental study of pure or abrasive water jet cutting is complex to carry out, the numerical simulation of this process stands as an attractive alternative. Such a simulation relies on the coupling of numerical tools devoted o...

The Discussers congratulate the Authors for their relevant work. The paper provides interesting results of CFD simulation of turbulent circular jets impinging vertically on a flat plate. Three different models were used, the realizable kmodel, the kSST model, and the RSM model, and compared to experimental data from Rajaratnam et al. (2010) and Giralt et al. (1977). Many characteristics of the ...

This paper reports an investigation into the use of CFD methods for modelling the combined fluid flow and heat transfer in a generic combustor heatshield geometry typical of current aeroengine designs. The study describes the development and testing of a conjugate heat transfer methodology, to allow the CFD code to predict the heat exchange in both fluid and solid regions of the solution domain...

Abstract—A cold, thin film of liquid impinging on an isothermal hot, horizontal surface has been investigated. An approximate solution for the velocity and temperature distributions in the flow along the horizontal surface is developed, which exploits the hydrodynamic similarity solution for thin film flow. The approximate solution may provide a valuable basis for assessing flow and heat transf...

Impinging jets have received considerable attention during the last decade. The reason is mainly due to their inherent characteristics of high rates of heat transfer besides having simple geometry. Thus most practical applications of jet impingement occur in industries where the heat transfer requirements have exceeded capacity of ordinary heating and cooling techniques. This work presents and ...

A 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 on the bottom of the outer cylinder which is designated as θ=0°. The outer cylinder is partially opened at the top with a width of W=30mm and is kept at constant t...