This study concerns a monitoring technique based on vibration measurements for identifying the presence of an acoustic source in fluid-filled pipe conveying turbulent flow. In such situation, source-induced vibrations can be smeared with flow-induced vibrations, which hinders detection. To increase signal-to-noise ratio (SNR), beamforming techniques applied to measured by array accelerometers m...

Small-amplitude fast vibrations and small surface micropatterns affect properties of various systems involving wetting, such as superhydrophobic surfaces and membranes. We review a mathematical method of averaging the effect of small spatial and temporal patterns. For small fast vibrations, this method is known as the method of separation of motions. The vibrations are substituted by effective ...

Recent studies have indicated that plantar-based vibration may be an effective approach for the prevention and treatment of osteoporosis. We addressed the hypothesis of whether the plantar vibration operated by way of the skeletal muscle pump, resulting in enhanced blood and fluid flow to the lower body. We combined plantar stimulation with upright tilt table testing in 18 women aged 46-63 yr. ...

A generalized variational equation based on the extended Hamilton’s principle is presented as the starting point for a procedure from which wake-body models for the two-dimensional vortex-induced vibration of a cylinder can be derived. The case of an elastically mounted cylinder with a transverse degree-of-freedom in a uniform flow is offered as a ‘‘model problem’’ through which this derivation...

NEW FINDINGS What is the central question of this study? Acute skeletal muscle satellite cell (SC) activation is associated with skeletal muscle hypertrophy. Although the quantity of SCs has been reported to increase following a single bout of resistance exercise, data on muscle fibre type-specific SC quantity and/or activation status after a single bout of vibration is presently lacking. What ...

The energy-conversion stability of hydropower is critical to satisfy the growing demand for electricity. In low-head plants, a gravitational surface vortex easily generated, which causes irregular shock vibrations that damage turbine performance and input-flow stability. complex fluid dynamic problem with high nonlinear features. Here, we thoroughly investigate its essential hydrodynamic proper...

The fingers of seven women with primary Raynaud's phenomenon (PRP), 10 female controls, seven men with vibration induced white finger (VWF), and eight male controls were exposed to vibration and the relative change in finger capillary blood flow was measured by an atraumatic 133xenon washout technique without and during proximal nervous blockade. All four groups showed a vasoconstriction to vib...

In this paper we present numerical results of the dynamic response to fluid forcing on an elastically mounted rigid cylinder in low-Reynolds flow, allowed to oscillate transverse to a free stream. A vortex method is implemented to solve the two-dimensional Navier-Stokes equation in terms of vorticity. The Reynolds numbers ranges from 90 to 170, a regime that is fully laminar. The vortex pattern...

The risk of vibration-induced fatigue in process pipework is usually assessed through vibration measurements. For small-bore pipework, integrity personnel would measure the and refer to widely used charts quantify fatigue. If levels are classified as OK, no action required on behalf operators. However, if it a CONCERN or PROBLEM level, strain measurements adequately life assessment. In this pap...

The vibration of centrifugal pumps, running at both best efficiency point (BEP) and at low flow, is of interest to both pump designers and users. This vibration is responsible for the poor seal and bearing life and reduced mean time between failure (MTBF). The cause of vane pass vibration and multiples of this are explained in this paper. The causes of low flow vibrations are also explored. The...