M Fairweather, G K Hargrave, and T C Williams
Two-dimensional measurements of mean and fluctuating velocities, and shear stresses, within the wall jet region of impinging turbulent air and water jets have been obtained using a Digital Particle Image Velocimetry (DPIV) technique. The data gathered demonstrate that DPIV can be used to derive useful information in this type of flow, of value in improving understanding of what is a practically important flow configuration. The present air jet results, considered in detail, are in good agreement with earlier measurements in similar flows gathered using laser Doppler anemometry, although significant differences do occur with previous hot wire anemometer measurements.
The impingement of a jet on a solid flat surface is a flow configuration of interest in many engineering applications, including cooling, heating, and drying processes, vertical take-off and landing aircraft, and ventilation during mining and tunnelling activities. It is also encountered in evaluations of the consequences of accidental releases of flammable material performed as part of safety and risk assessments on chemical and process plant, and transportation systems.
The orthogonally impinging jet has been the subject of renewed interest lately, not only because of its practical importance, but also because it represents an important test case for ...