In order to reduce aerodynamic noise radiated from the turbulent wake of bluff bodies, vorticity structures and flow field around a rotating circular cylinder at Reynolds numbers between 102 and 104 were numerically investigated. Vorticity structures and resultant aerodynamic noise is strongly dependant on the velocity ratio, which is defined as flow velocity over rotational speed to the cylind...

with the prolonged use of domestic centrifugal pump, due to erosion, corrosion and an unbalance the sever vibration of the pump are resulted. an erratic sound coming out of pump makes the user uncomfortable. here, tuned vibration absorber (tva) is used as a vibration controlling device. it is designed to reduce the rms velocity below 20% of the circumferential speed, at which the impeller is ba...

We present here a new ultrasonic diagnosis technique in natural, porous rocks. This method, based on the ultrasonic velocity changes, allows us to measure the transient spacial distribution of two liquids (water and oil) in a sandstone.

An elastic wave propagating in a metal loses a portion of its energy from scattering caused by acoustic impedance differences existing at the boundaries of anisotropic grains. Theoretical scattering models capture this phenomena by assuming the incoming wave is described by an average elastic moduli tensorC0 i jkl (x) that is perturbed by a grain with elasticityCi jkl (x ′) where the scattering...

In this study, aerodynamic and acoustic measurements were obtained in a dynamic mechanical model of the larynx and vocal tract. The model consisted of a uniform duct, intersected by a pair of sinusoidally oscillating shutters. A controlled airflow along the duct was periodically disturbed by the action of the shutters and pressure, and flow velocity measurements were obtained in the region down...