Dohn Davenport (cornvise6)

The measurements and simulations reveal that voice directivity in singing is affected if the mouth opening is changed significantly. The measurements show that the torso generates side lobes due to diffraction and reflections at frequencies related to the torso's dimensions.A vibrating surface in contact with a fluid experiences a reaction force that is related to the velocity of the surface. In the case of a harmonic vibration, the acoustic radiation impedance provides a useful measure of the harmonic force resulting from a harmonic velocity of the surface. More generally, the radiation impulse response, which is the temporal Fourier transform of the radiation impedance, provides the basis for a convolution approach to evaluate both the time-dependent force and the energy transfer into the fluid resulting from a time-dependent velocity of a fluid-loaded vibrating surface for interior and external problems. B02 Important properties of the radiation impulse responses are presented using the Kirchhoff Surface Integral Equation and Fourier transforms. A universal form of the radiation impulse response, which consists of a weighted Dirac delta function and a baseband function, is presented. The time-dependent force and energy transfer into a fluid resulting from the space-time normal velocity of a spherical surface is presented to simply illustrate the generalized radiation impulse response approach for exterior three-dimensional radiation problems.The lockdown that Madrid has suffered during the months of March to June 2020 to try to control and minimize the spread of COVID-19 has significantly altered the acoustic environment of the city. The absence of vehicles and people on the streets has led to a noise reduction captured by the monitoring network of the City of Madrid. In this article, an analysis has been carried out to describe the reduction in noise pollution that has occurred and to analyze the changes in the temporal patterns of noise, which are strongly correlated with the adaptation of the population's activity and behavior to the new circumstances. The reduction in the sound level ranged from 4 to 6 dBA for the indicators Ld, Le, and Ln, and this is connected to a significant variation in the daily time patterns, especially during weekends, when the activity started earlier in the morning and lasted longer at midday, decreasing significantly in the afternoon.In this study, we design a type of rotationally symmetric lattice with curved beams and investigate the wave propagation properties of the structure. The analytical model of the structure is established to obtain the mass and stiffness matrices first. Because the dimensions of the mass and stiffness matrices will become very large if the structure is meshed with a number of small elements, we introduce the symplectic solution method to overcome the above difficulties of solving the eigenvalue problem. The effects of geometrical parameters and slenderness ratios on the distributions of bandgaps and variations of group velocities are investigated. We also numerically investigate the dynamic wave dispersion behavior and the transient responses of displacement and transmission coefficients in lattices subjected to excitations. Excellent agreement is obtained between the results obtained by the symplectic solution method and numerical simulations. The special wave-attenuation property of this type of structure is demonstrated and validated through experimental testing. The measured transmission coefficients in lattices with different geometrical parameters and slenderness ratios are in good agreement with the numerical simulations. The work provides a method for calculating wave behaviors in lattices and obtains lower bandgaps and directional wave propagation.An experimental campaign was undertaken to identify the effects posed by flow recirculation on the dynamic performance and acoustic emissions of an isolated rotor, operating in hover in a sealed anechoic cham