this paper presents a k- turbulence model for simulation of steady current and itsinduced vortex shedding caused by the presence of an offshore pipeline. performance of the modelaround a circular cylinder above a wall with gap to diameter ratios of 0.1, 0.35 and 0.5 underdifferent flow regimes with reynolds numbers of 1500, 2500 and 7000 is studied. the flow field iscomputed with solving the re...

We discuss the nonzero frequency noise of heat current with explicit example energy carried by thermal photons in a circuit. Instead standard circuit modeling that gives convenient way predicting time-averaged current, we describe setup composed two resistors forming baths collections bosonic oscillators. In terms average transport this model leads to identical results conventional one, but bes...

In this study, the numerical analysis of turbulent flow and heat transfer of double pulsating impinging jets on a flat surface has been investigated. The unsteady two-dimensional numerical solution for two similar and dissimilar jets was performed using the RNG k-ε model. The results showed that the RNG k-ε model has more satisfactory predictions of the Nusselt number distribution. Comparisons ...

Abstract— In this paper, input impedance of a vertical rod under lightning stroke is first computed by applying the method of moments (MoM) on the Maxwell’s equations. The circuit model is then achieved through applying modified vector fitting (MVF) on the computed input impedance. After then the equivalent circuit is again extracted for a few values of soil conductivity and rod radius. Finally...

This paper presents a one-cycle-average (OCA) discrete-time model for PWM switched dc-dc converters operating in discontinuous conduction mode (DCM). The closed-loop system is considered in the presence of circuit parasitic. This model provides the exact OCA values of the output voltage and inductor current considering the conduction losses in the switching stage components. It also provides th...

This article is concerned with investigating the nonlinear dynamics of cylindrical resonator a wave solid-state gyroscope. The nonlinearity oscillations caused by properties electrostatic control sensors considered. derived taking into account finite ratio flexure to small gap sensors. equations electromechanical system that in interconnected form describe mechanical gyroscope and electrical ci...