Temperature gradient effects on acoustic and streaming velocities in standing acoustic waves resonator

•Temperature gradient effects on acoustic streaming were studied with PIV.•PIV technique was used for the measurements in a standing wave resonator.•Strong coupling between temperature gradient and acoustic streaming was underlined.•It highlights the formation of one sole vortex in place of two Rayleigh vortices.

This paper experimentally investigates the effects of an imposed axial temperature gradient in a cylindrical resonant cavity. The consequences on the acoustic velocity and acoustic streaming velocity are explored. The synchronised PIV (stands for Particle Image Velocimetry) technique was used in a 7 m long-standing wave air-filled acoustic resonator for the measurements. This method enabled the quantification of the changes in the velocity amplitudes due to the temperature gradient and highlighted the formation of one sole vortex in place of two Rayleigh vortices usually observed when acoustic streaming occurs.