The object of this study is a disc valve. In particular, the transient behaviour of the valve is studied as the valve moves from being fully closed and sealed to being fully open with steady-state flow of air established. The steady-state behaviour is well researched, the transient behaviour less so. A common assumption in valve design is that transient valve behaviour can be accurately represe...

In this paper we use hybrid systems to model and analyze the transient and steady-state behavior of multiple TCP flows that share a single common bottleneck link. The main contributions of this paper are (1) a characterization of the transient behavior of the flows, predicting their experimentally observed exponential synchronization and (2) a characterization of the steady-state regimen that i...

Rheological models for polymer solutions and melts based on the finitely extensible non-linear elastic (FENE) dumbbell theory are reviewed in this study. The FENE-P model that is a well-known Peterlin approximation of the FENE model, indicates noticeable deviation from original FENE predictions and also experimental results, especially in the transient flow. In addition, both FENE and FENE-P mo...

Transient responses of sap flow to step changes in wind speed were experimentally investigated in a wind tunnel. A Granier-type sap flow sensor was calibrated and tested in a cylindrical tube for analysis of its transient time response. Then the sensor was used to measure the transient response of a well-watered Pachira macrocarpa plant to wind speed variations. The transient response of sap fl...

The purpose of this paper is to analyze the flow field structure in transient state and performance of secondary injection system for thrust vectoring in divergent section of a two-dimensional nozzle. Secondary injection for thrust vectoring in a two-dimensional nozzle is studied by solving three-dimensional Reynolds-averaged equations by means of fluent solver. Spalart-allmaras model was used ...

Two-dimensional Poisson-Boltzmann and momentum equations are solved simultaneously to study the transient characteristics of electro-osmotic pumping in a rectangular microchannel. A finite difference scheme with variable grid spacing is used to calculate electric potential distribution. Time variations of velocity profiles are obtained by using a combined ADI-TDMA technique. Numerical solutions...

In single stage valves, the main spools are stroked directly by solenoid actuators. They are cheaper and more reliable than multistage valves. Their use, however, is restricted to low bandwidth and low flow rate applications due to the limitation of the solenoid actuators. Our research focuses on alleviating the need for large and expensive solenoids in single stage valves by advantageously usi...

This article investigates a generalised solution approach for transient viscoelastic flows employing consistent dynamic boundary conditions. Such a procedure vaunts three key properties independence of reference frame, problem dimension and constitutive equation type. Three different boundary condition protocols have been investigated, two transient and one steady, through a time-dependent incr...