Turbulent flow due to the interaction of two mutually perpendicular crossed turbulent streaming jets in water

Abstract

The food industry has studied turbulent streaming from an ultrasonic horn reactor, where the turbulent flow field can be modelled by a laminar jet flow that has a turbulent eddy viscosity [M. J. Lighthill, “Acoustic streaming,” J. Sound Vib. 61 (3), (1978) 391–418]. Work by Kumar (2006), Trujillo (2009) and others successfully compared the results with CFD models, have sparked interest in revisiting turbulent streaming by an ultrasonic horn, resulting in this presentation. Our demonstration studies the turbulent flow generated by the interaction between two mutually perpendicular crossed streaming jets – which both exhibit turbulent behavior. We are specifically interested in the flow field in the forward and backward directions defined by the bisecting line segment ±45 degrees from the axis of each streaming jet, with the line segment located in the plane shared by the jet axes. The apparatus consists of two Langevin ultrasonic transducers (125 kHz) that are both equipped with a half-wavelength exponential horn. The horns are slightly submerged in an open acrylic water tank to allow for viewing of the flow field. A particle image velocimeter (PIV) will be used to measure the turbulent flow velocity field in the plane of the interaction region aforementioned.The food industry has studied turbulent streaming from an ultrasonic horn reactor, where the turbulent flow field can be modelled by a laminar jet flow that has a turbulent eddy viscosity [M. J. Lighthill, “Acoustic streaming,” J. Sound Vib. 61 (3), (1978) 391–418]. Work by Kumar (2006), Trujillo (2009) and others successfully compared the results with CFD models, have sparked interest in revisiting turbulent streaming by an ultrasonic horn, resulting in this presentation. Our demonstration studies the turbulent flow generated by the interaction between two mutually perpendicular crossed streaming jets – which both exhibit turbulent behavior. We are specifically interested in the flow field in the forward and backward directions defined by the bisecting line segment ±45 degrees from the axis of each streaming jet, with the line segment located in the plane shared by the jet axes. The apparatus consists of two Langevin ultrasonic transducers (125 kHz) that are both equipped with a half-wavelength exponenti...