An analysis of fluctuations of speech wave, i.e., pitch, amplitude, and waveform, is a subject of growing interest for improvement in the quality of synthesized voice. However, little information with respect to the sound source itself in speech production is available, since it is difficult to measure fluid and acoustic motions within the larynx. The purpose of the present study is to clarify ...

Molecular dynamics (MD) simulation is used to study slip at the fluid-solid boundary in an unsteady flow based on the Stokes’ second problem. An increase in slip is observed in comparison to the steady flow for shear rates below the critical shear rate of the corresponding steady flow. This increased slip is attributed to fluid inertial forces not represented in a steady flow. An unsteady mathe...

In this paper, the locomotion of an autonomously navigated undersea vehicle that uses vorticity control propulsion is computationally simulated. The navigation procedure employs a set of vehicle geometric and state variables to predict the needed vehicle body deformations in order to pass through a set of predefined path-points. To simulate the movement of the vehicle, a two-dimensional unstead...

State-space representation of the unsteady aerodynamics of flapping flight" (2014). ARTICLE INFO ABSTRACT Article history: A state-space formulation for the aerodynamics of flapping flight is presented. The Duhamel's principle, applied in linear unsteady flows, is extended to non-conventional lift curves to capture the LEV contribution. The aspect ratio effects on the empirical formulae used to...

Control of a transitional laminar separation bubble using steady and unsteady 2D and 3D Tollmien-Schlichting (TS) like boundary-layer disturbances is investigated by means of direct numerical simulations. The specific influence of different disturbance modes which allow an effective reduction of the reverse-flow region is illustrated. It is shown that unsteady 2D or 3D control is more efficient...

We examined swimming behaviour, gait recruitment and post-exercise muscle glycogen, muscle lactate, plasma lactate and oxygen consumption in smallmouth bass (Micropterus dolomieu; 24-38 cm fork length) that voluntarily ascended a 25 m raceway against water velocities ranging from 40 to 120 cm s(-1). Physiological parameters were referenced to additional measurements made following exhaustive ex...

Investigations of flutter in transonic turbine cascades have shown that the movement of unsteady normal shocks has an important effect on the excitation of blades. In order to predict this phenomenon correctly, detailed studies concerning the response of unsteady blade pressures versus different parameters of an oscillating shock wave should be performed, if possible isolated from other flow ef...

In petroleum production, Produced Water Re-Injection (PWRI) has earned much interest among disposal methods of the produced water. However, presence of the contaminants in the produced waters usually results in formation damage in well bores and their surrounding fracture systems. In the present study, modeling of external cake formation on a fracture in unsteady-state conditions i...

The Unsteady Vortex-Lattice Method provides a medium-fidelity tool for the prediction of non-stationary aerodynamic loads in low-speed, but high-Reynolds-number, attached flow conditions. Despite a proven track record in applications where free-wake modelling is critical, other less-computationally-expensive potential-flow models, such as the Doublet-Lattice Method and strip theory, have long b...

A hardware-based approach for visualizing unsteady flow fields by means of Lagrangian-Eulerian advection is presented. The implementation allows texture advection to be performed completely on the graphics hardware in a single-pass rendering. We discuss experiences with the interactive visualization of unsteady flow fields that become possible due to the high visualization speed of the hardware...