The difference frequency technique for bubble size and doppler velocity measurements

Didenkulov, I. N.; Sutin, A. M.; Yoon, S. W.
July 2000
AIP Conference Proceedings;2000, Vol. 524 Issue 1, p333
Academic Journal
Bubbles in liquids are very resonant and nonlinear objects. Since nonlinear responses from a bubble can be easily observed at the resonance frequency in relatively low intensity acoustic fields, that makes possible bubble diagnostics. The present paper describes the feasibility of the difference frequency method. It is considered that the difference frequency signal is generated by a bubble cloud insonified with two primary waves of different frequencies. Incoherent difference frequency scattering from a bubble cloud is described theoretically. The difference frequency amplitude is shown to be proportional to the bubble density having resonance frequency close to the difference frequency. When bubbles move, a specific Doppler frequency shift arises in the nonlinear scattered field. A theory of the nonlinear Doppler effect for moving bubbles is described. It is shown, in particular, that the difference frequency Doppler shift strongly exceeds the linear Doppler shift when primary acoustic waves propagate from different directions relatively to a moving bubble. Experimental verification of the difference frequency bubble sizing and the Doppler velocity measurement are described.


Related Articles

  • Twenty-channel grating polychromator for millimeter wave plasma emission measurements. Cavallo, A.; Cutler, R. C.; McCarthy, M. P. // Review of Scientific Instruments;Jun88, Vol. 59 Issue 6, p889 

    A 20-channel grating instrument based on the Ebert–Fastie grating monochromator has been built to measure electron temperature profiles and electron temperature fluctuations in TFTR (tokamak fusion test reactor). Second-harmonic electron cyclotron emission for the plasma over the...

  • Silicon Microtube Technology Improves Fluid Measurements. Allan, Roger // Electronic Design;11/11/2002, Vol. 50 Issue 24, p38 

    Reports on the use of silicon microtube technology which permits accurate and efficient measurement of the density and specific gravity of fluids. Integrated sensing system instrument; Sensitivity measurement requirements; Effect of integrating the temperature controller.

  • Choice of the threshold level in a velocity-based conditional sampling procedure. Tabatabai, M.; Kawall, J. G.; Keffer, J. F. // Physics of Fluids A;Feb89, Vol. 1 Issue 2, p307 

    Analysis of velocity traces obtained in the intermittent region of a wake by means of a rake of hot-wire probes has clearly shown that many of the weak fluctuations observed in the outer, very low-intermittency-factor region of the flow are associated with the turbulent bulges and are not...

  • Scalar imaging velocimetry measurements of the velocity gradient tensor field in turbulent flows... Su, Lester K.; Dahm, Werner J.A. // Physics of Fluids;Jul96, Vol. 8 Issue 7, p1869 

    Reports on the formulation of flow field velocimetry based on scalar imaging measurements in terms of an integral minimization implementation. Minimization of weighted residuals of the conserved scalar transport equation to find velocity field; Insensitivity of results to noise at levels...

  • Scalar imaging velocimetry measurements of the velocity gradient tensor field in turbulent flows... Su, Lester K.; Dahm, Werner J.A. // Physics of Fluids;Jul96, Vol. 8 Issue 7, p1883 

    Reports on the use of scalar imaging velocimetry to experimental turbulent flow scalar field data to yield the first fully resolved, non-intrusive laboratory measurements of the spatio-temporal structure and dynamics of the full nine-component velocity gradient tensor field. Reynolds number...

  • A Laboratory Model of Urban Street-Canyon Flows. Jong-Jin Baik; Rae-Seol Park // Journal of Applied Meteorology;Sep2000, Vol. 39 Issue 9, p1592 

    Examines the urban street-canyon flow through a circulating water channel laboratory model. Construction of the experimental apparatus; Measurement of street-canyon wind velocities; Use of subgrid transport equations; Profile of normalized vertical velocity in different canyon locations.

  • Directional load-cell anemometric probe. Vallascas, Rinaldo; Porcu, Gian Franco // Review of Scientific Instruments;Aug1989, Vol. 60 Issue 8, p2740 

    A load-cell anemometric sensor is presented for simultaneous measurement of flow rates and flow direction of a fluid. The tests were carried out in steady flow conditions with air temperature of 28.5 ± 0.5 °C, flow-rate range of 10-20 m/s and a pressure of 101.1 kPa.

  • 3-D airflow visualized.  // Aviation Week & Space Technology;11/1/1993, Vol. 139 Issue 18, p72 

    Reports on a three-dimensional visualization of compressible turbulence as result of a study on computational fluid dynamics problems. Benefit of the joint study by the University of Minnesota and the United States Army High-Performance Computing Research Center; Reproduction of image.

  • A Correction Method for Turbulence Measurements with a 3D Acoustic Doppler Velocity Profiler. Hurther, D.; Lemmin, U. // Journal of Atmospheric & Oceanic Technology;Mar2001, Vol. 18 Issue 3, p446 

    Presents a study which proposed a method to reduce the noise contribution to mean turbulence parameters obtained by three dimensional acoustic Doppler velocity profiler measurements. Experimental setup: Results and discussion; Conclusions.


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics