The paper presents the results of vibroacoustic investigations and the measurements of the acoustic pressure level (noise) of a transformer model. The measurements were taken at a full transformer load in two operation conditions: at a producer packeted core and at unpacketed core. Unpacketing consisted in loosing the screws pressing the particular core plates. Mechanical vibrations were regist...

In this paper, a fully coupled vibro-acoustic finite element model (FEM) is developed to characterize the structural and acoustic coupling of a flexible thin shell by a cylinder-like cavity. The combined integral-modal approach is used to handle the acoustic pressure inside the cavity. Based on the modal proposed, the impact excitation effect on the vibro-acoustic behavior of the coupled system...

AR = cavity aspect ratio a = speed of sound b = cavity half-width ~ C = dynamic compressibility c = phase speed cp = specific heat at constant pressure f = frequency H = cavity depth k = wave number m = propagation constant P = pressure Pr = Prandtl number R = reflection coefficient p = acoustic pressure pi = initial pulse amplitude Re = acoustic Reynolds number s = cavity spacing T = temperatu...

A multilayer encapsulated coating has been developed for underwater acoustic attenuation purposes. This coating provides an option for electronically activating encapsulated piezoelectric devices to increase the coatings passvie sound attenuation performance through active control methods. These methods include the ability to sense the incident and reflected acoustic pressure field and produce ...

Introduction: Mechanical index (MI) is used for quantifying acoustic cavitation and the relationship between acoustic pressure and the frequency. In this study, modeling of the MI was applied to provide treatment protocol and to understand the effective physical processes on reproducibility and gene expression of fibroblast cells. Skin damage can occur of burn, cuts, abrasions ...

This research has been carried out to determine the marine propeller hydro-acoustic characteristics by Reynolds-Averaged Navier-Stokes (RANS) solver in both uniform and non-uniform wake flow at different operating conditions Wake flow can cause changes in pressure fluctuation and gas effect on propeller noise spectrum. Noise is generated by the induced trailing vortex wake and induced pressure ...

A method is introduced for using measurements made in water of the nonlinear acoustic pressure field produced by a high-intensity focused ultrasound transducer to compute the acoustic pressure and temperature rise in a tissue medium. The acoustic pressure harmonics generated by nonlinear propagation are represented as a sum of modes having a Gaussian functional dependence in the radial directio...

Fast-response pressure sensitive paint (PSP) is used in this work to measure and analyze the acoustic pressure field in a rectangular cavity. The high spatial resolution and fast frequency response of PSP effectively captures the spatial and temporal detail of surface pressure resulting in the acoustic pressure field. In this work, a high-speed camera is used to generate a continuous time recor...

Electrical stimulation and other modalities are recommended for treatment of pressure ulcers in spinal cord injury patients but their use may be limited by clinical contraindications such as necrosis and infection. Acoustic pressure wound therapy can be used to address infection and has no known contraindications related to wound status. A retrospective nonconsecutive study was conducted involv...

We present an acoustic rendering approach visualizing the listener-specific contribution of frequency-dependent pressure fields on a scene geometry with acoustic reflection and scattering properties. Our method facilitates the evaluation of simulated acoustics showing the effect of simulation parameters like absorption and scattering. The image-based spatial localization of acoustic properties ...