Hydrodynamisch‐akustische Untersuchungen

König, Walter

doi:10.1002/andp.18912780404

Cited by 30 publications

(6 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For * glauber@pq.cnpq.br † bruus@fysik.dtu.dk a given particle, the acoustic interaction force is caused by the scattered waves from the other particles. Investigations on this force dates back to the nineteenth century, when Bjerknes studied the mutual force between a pair of bubbles [11], and the analysis performed by König on the acoustic interaction force between two rigid spheres [12]. Subsequently, this force was investigated considering short-range interaction between particles of the types rigid-rigid [13,14], bubble-bubble [15,16], bubble-rigid [17], and bubble-droplet [18]; whereas longrange rigid-rigid [19] and bubble-bubble [20,21] interactions have also been studied.…”

Section: Introductionmentioning

confidence: 99%

Acoustic interaction forces between small particles in an ideal fluid

2014

View full text Add to dashboard Cite

We present a theoretical expression for the acoustic interaction force between small spherical particles suspended in an ideal fluid exposed to an external acoustic wave. The acoustic interaction force is the part of the acoustic radiation force on one given particle involving the scattered waves from the other particles. The particles, either compressible liquid droplets or elastic microspheres, are considered to be much smaller than the acoustic wavelength. In this so-called Rayleigh limit, the acoustic interaction forces between the particles are well approximated by gradients of pair-interaction potentials with no restriction on the interparticle distance. The theory is applied to studies of the acoustic interaction force on a particle suspension in either standing or traveling plane waves. The results show aggregation regions along the wave propagation direction, while particles may attract or repel each other in the transverse direction. In addition, a mean-field approximation is developed to describe the acoustic interaction force in an emulsion of oil droplets in water.

show abstract

Section: Introductionmentioning

confidence: 99%

Acoustic interaction forces between small particles in an ideal fluid

2014

View full text Add to dashboard Cite

show abstract

“…So, the distribution of acoustic radiation pressure on the particle changes during its rotation and leads to an additional orientation dependent acoustic radiation torque. The influence of acoustic radiation forces on particle orientations is a well-known effect for small non-spherical particles with r ≪ λ [45,46], but this experiment shows that this influence is also large enough to influence the rotation by the acoustic VT. Particles with a larger degree of non-sphericalness did not even start to rotate in this set of experiments.…”

Section: Rotation Detection Validationmentioning

confidence: 70%

Rotational speed measurements of small spherical particles driven by acoustic viscous torques utilizing an optical trap

Lamprecht

Goering

Schaap

et al. 2021

J. Micromech. Microeng.

View full text Add to dashboard Cite

Two orthogonal standing acoustic waves, generated by piezoelectric excitation, can form a two-dimensional pressure field in microfluidic devices. A phase difference of the excitation waves can be employed to rotate spherical µm-sized silica particles by a torque mediated through the viscous boundary δ around the particle. The measurement of the rotational rate is, so far, limited to high-speed cameras and their frame rate, and gets increasingly difficult when the sphere gets smaller. We report here a new method for measuring the rotational rate of µm sized spherical particles. We utilize an optical trap with high-speed position detection to overcome the frame rate limitation of wide field image recording. The power spectrum of an optically trapped, rotating particle reveals additional peaks corresponding to the rotational frequencies—compared to a non-rotating particle. We validate our method at low rotational rates against high-speed video observation. To demonstrate the potential of this method we addressed a recent controversy about the rotation of particles with a relatively large viscous boundary layer δ. We measured steady-state rotational rates up to 229 Hz (13.8 × 103 rpm) for a particle with a radius R ≈ δ. Recent numerical research suggests that in this regime the existing theoretical approach (valid for R ≫ δ ) overpredicts the steady-state rotational rate by a factor of 10. With our new method we also confirm the numerical results experimentally.

show abstract

“…form larger particles from smaller ones. The interaction of spherical particles in a gas in a sound wave is determined by the theory of Kӧenig [8]. The radial component of the Kӧenig force have the form [9]:…”

Section: Effect Of Ultrasound On the Mixture Of Nanoparticles And Soo...mentioning

confidence: 99%

Carbon Nanoparticles in the Radiation and Acoustic fields the Vicinity of the Arc Discharge

Shneider

2016

54th AIAA Aerospace Sciences Meeting

View full text Add to dashboard Cite

show abstract

Hydrodynamisch‐akustische Untersuchungen

Abstract: 11. l i u b e r die. K r a f t e xwischeii x w e i K u g e l n i l l e i n e r s c h w i i igciideii 14'liissigkeit und iiber d i e E n t s t e h u n g der Kuiidt'sch(-ri S t a II b f i g u r en.

Cited by 30 publications

References 4 publications

Acoustic interaction forces between small particles in an ideal fluid

Acoustic interaction forces between small particles in an ideal fluid

Rotational speed measurements of small spherical particles driven by acoustic viscous torques utilizing an optical trap

Carbon Nanoparticles in the Radiation and Acoustic fields the Vicinity of the Arc Discharge

Contact Info

Product

Resources

About