Impinging Air Jets on Flat Surfaces at Low Reynolds Numbers

Abstract Many practical applications and developing devices assume impinging jets to be spreading on smooth surfaces or in narrow gaps with controlled wall roughness. This work presents results of an experimental investigation and a CFD numerical modeling regarding the impact of a laminar circular air jet on a wall with smooth surface. First, the tests are directed to the experimental study of a jet impinging on a perpendicular wall, then a CFD study in the same flow conditions is performed. Both cases study the evolution of the flow in the area where the jet is deflected from axial to radial direction. The non-stationary jet dynamics is characterized by small time scales, while in the stagnation region small length scales occur in the same time, so direct visualizations using high speed/resolution camera are performed. Because not all the flow parameters can be inferred from experiments, the visualizations are correlated with corresponding numerical simulations. The present work brings the opportunity for new numerical simulations on jets impinging on walls with more complex geometries, where the right choosing of numerical test cases and parameters is of great importance.