Micropropulsion by an acoustic bubble for navigating microfluidic spaces

Lab on a Chip ◽  
2015 ◽  
Vol 15 (6) ◽  
pp. 1554-1562 ◽  
Author(s):  
Jian Feng ◽  
Junqi Yuan ◽  
Sung Kwon Cho
Keyword(s):  
Acoustic Excitation ◽  
Gaseous Bubble

This paper describes an underwater micropropulsion principle where a gaseous bubble trapped in a suspended microchannel and oscillated by external acoustic excitation generates a propelling force.

scholarly journals The Characteristics of Debye Effect Magnetic Field Under Acoustic Excitation

2021 ◽  
Vol 1885 (4) ◽  
pp. 042021
Author(s):  
Yujing Xu ◽  
Mengchun Pan ◽  
Qi Zhang ◽  
Dixiang Chen ◽  
Zhongyan Liu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Acoustic Excitation

scholarly journals Vibration responses of a satellite subjected to acoustic excitation at launch stage

2021 ◽  
Vol 1786 (1) ◽  
pp. 012034
Author(s):  
Jie Zhang ◽  
Weihua Xie ◽  
Jiacong Yin ◽  
liu Huiliang ◽  
Jiang Zhou
Keyword(s):  
Acoustic Excitation ◽  
Vibration Responses

Effects of Acoustic Excitation on a Swirling Diffusion Flame

2010 ◽  
Vol 132 (12) ◽  
Author(s):  
Michael E. Loretero ◽  
Rong F. Huang
Keyword(s):  
Flow Field ◽  
Bluff Body ◽  
Excitation Frequency ◽  
Excitation Amplitude ◽  
Mie Scattering ◽  
Flame Length ◽  
Laser Doppler Velocimeter ◽  
Scattering Method ◽  
Acoustic Excitation ◽  
Characteristic Modes

A swirling double concentric jet is commonly used for nonpremixed gas burner application for safety reasons and to improve the combustion performance. Fuel is generally spurted at the central jet while the annular coflowing air is swirled. They are normally separated by a blockage disk where the bluff-body effects further enhance the recirculation of hot gas at the reaction zone. This paper aims to experimentally investigate the behavior of flame and flow in a double concentric jet combustor when the fuel supply is acoustically driven. Laser-light sheet assisted Mie scattering method has been used to visualize the flow, while the flame lengths were measured by a conventional photography technique. The fluctuating velocity at the jet exit was measured by a two-component laser Doppler velocimeter. Flammability and stability at first fuel tube resonant frequency are reported and discussed. The evolution of flame profile with excitation level is presented and discussed, together with the reduction in flame length. The flame in the unforced reacting axisymmetric wake is classified into three characteristic modes, which are weak swirling flame, lifted flame, and transitional reattached flame. These terms reflect their primary features of flame appearances, and when the acoustic excitation is applied, the flame behaviors change with the excitation frequency and amplitude. Four additional characteristic modes are identified; e.g., at low excitation amplitudes, wrinkling flame with a blue annular film is observed because the excitation induces vortices in the central fuel jet and hence gives rise to the wrinkling of flame. The central jet vortices become larger with the increase in excitation amplitude and thus lead to a wider and shorter flame. If the excitation amplitude is increased above a certain value, the central jet vortices change the rotation direction and pacing with the annular jet vortices. These changes in the flow field induce large turbulent intensity and mixing and therefore make the flame looks blue and short. Further increase in the excitation amplitude would lift the flame because the flow field would be dramatically modified.

Vortex evolution in a round jet

1968 ◽  
Vol 31 (3) ◽  
pp. 435-448 ◽  
Author(s):  
H. A. Becker ◽  
T. A. Massaro
Keyword(s):  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Ring Vortex ◽  
Acoustic Excitation ◽  
Light Scatter ◽  
Turbulent Eddies ◽  
Cylindrical Vortex ◽  
Highly Sensitive ◽  
Pure Tones ◽  
Axisymmetrical Jet

A study has been made of the varicose instability of an axisymmetrical jet with a velocity distribution radially uniform at the nozzle mouth except for a laminar boundary layer at the wall. The evolutionary phenomena of instability, such as the rolling up of the cylindrical vortex layer into ring vortices, the coalescence of ring vortex pairs, and the eventual disintegration into turbulent eddies, have been investigated as a function of the Reynolds number using smoke photography, stroboscopic observation, and the light-scatter technique.Emphasis has been placed on the wavelength with maximum growth rate. The jet is highly sensitive to sound and the effects of several types of acoustic excitation, including pure tones, have been determined.

Double Nuclear Magnetic Resonance in NaClO3 by Acoustic Excitation

1972 ◽  
Vol 32 (2) ◽  
pp. 579-579 ◽  
Author(s):  
Tatsuo Kanashiro ◽  
Takashi Ohno ◽  
Toshihiko Taki ◽  
Mitsuo Satoh
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Acoustic Excitation ◽  
Nuclear Magnetic
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