PIV measurements of 3-dimensional acoustic Rayleigh streaming in a square cross-section standing wave resonator

Ida Reyt , Yasser Rafat , Luc Mongeau , Rani Taher , Hélène Bailliet (1)

1 PPrime [Poitiers] - Institut Pprime [UPR 3346]

Rayleigh streaming may hamper the efficiency of thermoacoustic devices through the creation of convective heat transfer between the stack and heat exchangers. A better understanding and characterization of Rayleigh streaming flows is useful to assess their impact on the efficiency of thermoacoustic engines. Streaming flows in idealized configurations such as between infinite parallel plates or in cylindrical waveguides has been investigated in earlier studies. As a first step towards the investigation of streaming in more realistic configurations, streaming flows in a resonator with a square cross-section was investigated. Non-symmetric streaming structures were anticipated. For a horizontal waveguide, velocity fields within the horizontal plane were measured using Particle Image Velocimetry (PIV). These measurements were performed at several vertical positions so that three-dimensional streaming cell structures could be reconstructed from the different planar streaming velocity fields. The acoustic streaming within the boundary layer was also studied by zooming near the wall of the channel. The three dimensional streaming cells reconstructed by combining the data in the different planes reveals the nature of the streaming flow structures in the square cross-section standing wave tube. Streaming amplitudes were quantified and were compared with predictions from theoretical models.

Mots clés: Acoustic streaming; PIV; Three dimensional

Domaines: Acoustique [physics.class-ph]

Ida Reyt, Yasser Rafat, Luc Mongeau, Rani Taher, Hélène Bailliet. PIV measurements of 3-dimensional acoustic Rayleigh streaming in a square cross-section standing wave resonator. Acoustics 2012, Apr 2012, Nantes, France. ⟨hal-00810934⟩