BEAM VIBRATION INDUCED ACOUSTIC STREAMING

The purpose of this research is to investigate the
beam vibration induced acoustic streaming. Analytical
results show that the beam vibrating in standing
waveforms scatters the acoustic waves into the free
space with a larger attenuation coefficient and
longer propagating traveling wavelength than those of
the plane wave. In contrast to a constant Reynolds
stress in the plane wave, the Reynolds stress
generated by such acoustic wave is expected to drive
the free space streaming away from the anti-nodes and
towards nodes of the standing wave vibration. The
sonic and ultrasonic streamings within the channel
between the vibrating beam and a parallel stationary
beam are also investigated. The sonic streaming is
found to be mainly the boundary layer streaming
dominating the whole channel while the ultrasonic
streaming is clearly composed of two boundary layer
streamings near both beams and a core region
streaming, which is driven by the streaming velocity
at the edge of the boundary layer near the vibrating
beam. The acoustic streaming cooling effect is
analyzed. The hysteresis and driven cavity phenomena
are explored with discovery of interesting
interactions among the primary eddies.

Autorentext

Dr. Qun Wan received the B.E. degree from University of Scienceand Technology of China in 1996, the M.S. degree from theNational University of Singapore in 2001, and the Ph.D. degreefrom North Carolina State University in 2003. His interestfocuses on CFD, electronics cooling and packaging. He isaffiliated with ASME and a senior member of IEEE.

Klappentext

The purpose of this research is to investigate thebeam vibration induced acoustic streaming. Analyticalresults show that the beam vibrating in standingwaveforms scatters the acoustic waves into the freespace with a larger attenuation coefficient andlonger propagating traveling wavelength than those ofthe plane wave. In contrast to a constant Reynoldsstress in the plane wave, the Reynolds stressgenerated by such acoustic wave is expected to drivethe free space streaming away from the anti-nodes andtowards nodes of the standing wave vibration. Thesonic and ultrasonic streamings within the channelbetween the vibrating beam and a parallel stationarybeam are also investigated. The sonic streaming isfound to be mainly the boundary layer streamingdominating the whole channel while the ultrasonicstreaming is clearly composed of two boundary layerstreamings near both beams and a core regionstreaming, which is driven by the streaming velocityat the edge of the boundary layer near the vibratingbeam. The acoustic streaming cooling effect isanalyzed. The hysteresis and driven cavity phenomenaare explored with discovery of interestinginteractions among the primary eddies.