Related papers: On indirect noise in multicomponent nozzle flows
The identification of sound sources is a common problem in acoustics. Different parameters are sought, among these are signal and position of the sources. We present an adjoint-based approach for sound source identification, which employs…
Mid-air acoustic streaming, where ultrasound induces steady fluid motion, could significantly affect the perception of haptic sensations, stability of levitation systems, and enable controlled transfer of odours (smells) through air by…
We modified the modal expansion, which is the traditional method used to calculate thermal noise. This advanced modal expansion provides physical insight about the discrepancy between the actual thermal noise caused by inhomogeneously…
In a fissile material, the inherent multiplicity of neutrons born through induced fissions leads to correlations in their detection statistics. The correlations between neutrons can be used to trace back some characteristics of the fissile…
An overexpanded jet in a truncated ideally contoured nozzle is found to feature a tonal behavior. The flow field is investigated to understand its origin and show how it modifies side-load properties. The temporal and spatial organization…
A new dispersion equation is obtained for a non-equilibrium medium with an exponential relaxation model of a vibrationally excited gas. We have researched the dependencies of the pump source and the heat removal on the medium thermodynamic…
This work develops a spherical-multipole expansion of Goldstein's acoustic analogy, for the prediction of tonal noise from rotating propellers. The acoustic field is expressed through spherical multipoles, which separate source integrals…
The relativistic theory of hydrodynamic fluctuations, or noise, is derived and applied to high energy heavy ion collisions. These fluctuations are inherent in any space-time varying system and are in addition to initial state fluctuations.…
It is suggested that the dynamics of liquid water has a component consisting of O^{-2z} (oxygen) anions and H^{+z} (hydrogen) cations, where z is a (small) reduced effective electron charge. Such a model may apply to other similar liquids.…
Some experimental results of correlation functions in Bose-Einstein interferometry measurements exhibit a non smooth behaviour - oscillations. Possible origin of such a behaviour in non-trivial spatial distribution of the source is…
The analysis of noise-induced escape in populations of bistable elements is challenging, because nonlinearity, coupling, and noise all play essential roles. We show that the interplay of these three factors yields three qualitatively…
Recent research on the dynamics of certain fluid dynamical instabilities shows that when there is a slow invariant manifold subject to fast timescale instability the dynamics are extremely sensitive to noise. The behaviour of such systems…
An experiment is proposed to test a previously developed theory of the hydrodynamics of a nonequilibrium heat current-induced superfluid-normal interface. It is shown that the interfacial ``trapped'' second sound mode predicted by the…
The injection of transverse jets into supersonic compressible crossflows represents a fundamental configuration relevant to a spectrum of high-speed applications. The intricate interactions arising between the crossflow and the injected jet…
Impinging compressible jets may cause deafness and material fatigue due to immensely loud tonal noise. It is generally accepted that a feedback mechanism similar to the screech feedback loop is responsible for impinging tones. The close of…
Quantum droplets are ultradilute liquid states which emerge from the competitive interplay of two Hamiltonian terms, the mean-field energy and beyond-mean-field correction, in a weakly interacting binary Bose gas. We relate the formation of…
The dynamics of sound in a fluid is intrinsically nonlinear. We derive the consequences of this fact for the analogue gravitational field experienced by sound waves, by first describing generally how the nonlinearity of the equation for…
Lighthill's theory of sound generation was developed to calculate acoustic radiation from a narrow region of turbulent flow embedded in an infinite homogeneous fluid. The theory is extended to include a simple model of non-isothermal medium…
In natural settings, intermittent dynamics are ubiquitous and often arise from a coupling between external driving and spatial heterogeneities. A well-known example is the generation of transient, turbulent puffs of fluid through a pipe…
An analysis is presented for the evaluation of the acoustic field of a rotating source in a non-uniform potential flow. Other than the restriction to low flow Mach numbers, the method is exact and general. The variation in radiation…