Much attention has been given to the possibility of enhancing the heat transfer rate by superimposing pulsation on a mean flow inside a confined passageway. Industrial applications can be found in Stifling engines and reciprocating cycles, to name a few. A perusal of the relevant literature reveals that pulsating flows in a pipe and the attendant heat transfer have been the subject of several a...

The article deals with pneumatic and hot wire anemometry measurement on subsonic axi-symmetric air ejector. Performances of the ejector with and without pulsations of primary flow are compared, measuring of characteristic pressures and mass flow rates are performed and ejector efficiency is evaluated. The pulsations of primary flow are produced by a synthetic jet generator, which is placed in t...

An inherent problem of single-phase rectifiers is the existence of a pulsating portion in the input power, which pulsates at twice the grid frequency. If this pulsating power is transferred to the DC-link, it causes a significant amount of second-order harmonic at the output voltage. Since in many applications, such a high level of DC oscillation is not acceptable, so the pulsating power must b...

Voice production involves sound generation by a confined jet flow through an orifice (the glottis) with a time-varying area. Predictive models of speech production are usually based on the so-called quasi-steady approximation. The flow rate through the time-varying orifice is assumed to be the same as a sequence of steady flows through stationary orifices for wall geometries and flow boundary c...

We report the measurement of fluid velocity on a semiconducting single-walled carbon nanotubes film in a microfluidic channel. To investigate the mechanism related to electrical signal change, we performed various experiments along with changing the flow velocity, the ion concentration and liquid viscosity, etc. Our result suggests that the sensing of flow velocity is a closely related to a pul...

We study an eigenvalue problem associated with a reaction-diffusionadvection equation of the KPP type in a cellular flow. We obtain upper and lower bounds on the eigenvalues in the regime of a large flow amplitude A 1. It follows that the minimal pulsating traveling front speed c∗(A) satisfies the upper and lower bounds C1A ≤ c∗(A) ≤ C2A. Physically, the speed enhancement is related to the boun...

It is now accepted that the physical forces in ultrasonic cleaning are due to strongly pulsating bubbles driven by the sound field. Here we have a detailed look at bubble induced cleaning flow by analyzing the transport of an individual particle near an expanding and collapsing bubble. The induced particulate transport is compared with a force balance model. We find two important properties of ...