scholarly journals Nonlinear Phenomena Induced by Finite-Amplitude Oscillation of Air Column in Closed Duct. Analysis of Acoustic Streaming.

1996 ◽  
Vol 39 (2) ◽  
pp. 280-286 ◽  
Author(s):  
Masaaki KAWAHASHI ◽  
Masahiro ARAKAWA
Keyword(s):  
Acoustic Streaming ◽  
Finite Amplitude ◽  
Nonlinear Phenomena ◽  
Amplitude Oscillation ◽  
Air Column

scholarly journals Michael Selwyn Longuet-Higgins. 8 December 1925—26 February 2016

2018 ◽  
Vol 65 ◽  
pp. 249-265
Author(s):  
Shahrdad G. Sajjadi ◽  
Julian C. R. Hunt
Keyword(s):  
Water Waves ◽  
Ocean Waves ◽  
Breaking Waves ◽  
Finite Amplitude ◽  
Nonlinear Phenomena ◽  
Physical Oceanography ◽  
Applied Mathematician ◽  
Geometrical Character ◽  
Tidal Streams ◽  
Quasi Crystals

Michael Longuet-Higgins was a geometer and applied mathematician who made notable contributions to geophysics and physical oceanography, particularly to the theory of oceanic microseism and to the dynamics of finite amplitude, sharp-crested wind-generated surface waves. The latter led to his pioneering studies on breaking waves. On a much larger scale, he showed how ocean waves produce currents around islands in the ocean. He considered wider aspects of the physics of waves, including wave-driven transport of sand along beaches, and the electrical effects of tidal streams. He also contributed to subjects of a geometrical character such as the growth of quasi-crystals, the assembly of protein sheaths in viruses, to chains of circle themes and to a wide variety of other topics. He was an extraordinary applied mathematician, using the simplest forms of mathematics to demonstrate and discover highly complex nonlinear phenomena. In particular, he often thought of problems involving water waves using his unique knowledge of geometry and then tested his theories by experiment. Along with Brooke Benjamin FRS, Sir James Lighthill FRS, Walter Munk FRS, John Miles and Andrei Monin, Michael Longuet-Higgins stands out as one of the towering figures of theoretical fluid dynamics in the twentieth century. His contributions will have a continuing influence on our attempts to understand better the processes that influence the oceans.

DC Flow Investigations in Thermoacoustic Prime Mover

2011 ◽  
Author(s):  
Richard Paridaens ◽  
Smaine Kouidri ◽  
Fathi Jebali Jerbi
Keyword(s):  
Linear Model ◽  
Acoustic Pressure ◽  
Acoustic Streaming ◽  
Secondary Flows ◽  
Nonlinear Phenomena ◽  
Prime Mover ◽  
First Order ◽  
Current Systems ◽  
Theoretical Results

In thermoacoustic device, the nonlinear phenomena are the source of secondary flows superimposed on the oscillating flow. To date, the acoustic streaming have been only characterized for progressive and standing waves in current systems. A method to characterize theoretically the secondary flows in thermoacoustic systems with more complex geometries is developed in this paper. This method is applied in the case of an annular thermoacoustic prime mover. The streaming fields are then provided. As the determination of the streaming fields requires the knowledge of the first order acoustic parameters, a linear model is used. The theoretical results of the acoustic pressure are compared to the experimental data. A relative error less than 10% is obtained, allowing the validation of the linear model.

Frequency Scaling at the Onset of Finite Amplitude Oscillation

1986 ◽  
Vol 41 (12) ◽  
pp. 1412-1414 ◽  
Author(s):  
H. Bruce Stewart
Keyword(s):  
Scaling Law ◽  
Finite Amplitude ◽  
Bifurcation Parameter ◽  
Frequency Scaling ◽  
Amplitude Oscillation

The onset of oscillation at non-zero finite amplitude is shown to be governed in the generic case by a scaling law for the frequency of oscillation f in terms of the bifurcation parameter μ – μc namely f ~ (μ – μ)c1/2. This law can be expected to hold whenever such a bifurcation occurs in a nondegenerate system without hysteresis.

Sign in / Sign up

Export Citation Format

Share Document