To improve the prediction accuracy of pollutant dispersion near a source, limiter for turbulent concentration diffusivity accounting travel time is introduced into Reynolds-averaged Navier–Stokes equations (RANS) and Eulerian model. We predict in two-dimensional street canyon three-dimensional building arrays via conventional modeling based on simplified gradient diffusion hypothesis limiter. T...

Many control schemes have been proposed for induction motor and permanent magnet synchronous motor control, which are almost highly complex and non-linear. Also, a simple and efficient method for unified control of the electric moto are rarely investigated. In this paper, a novel control method based on rotor flux orientation is proposed. The novelties of proposed method are elimination of q-ax...

The technique of obtaining high resolution, second order, oscillation free (TVD), explicit scalar difference schemes, by the addition of a limited antidiffusive flux to a first order scheme is explored and bounds derived for such limiters. A class of limiters is presented which includes a very compressive limiter due to Roe, and various limiters are compared both theoretically and numerically.

Both core accretion and disk instability appear to be required as formation mechanisms in order to explain the entire range of giant planets found in extrasolar planetary systems. Disk instability is based on the formation of clumps in a marginally-gravitationally unstable protoplanetary disk. These clumps can only be expected to contract and survive to become protoplanets if they are able to l...

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Continuous control over azimuthal flow and shear in the edge of the Large Plasma Device (LAPD) has been achieved using a biasable limiter which has allowed a careful study of the effect of flow shear on pressure-gradient-driven turbulence and transport in the LAPD. The LAPD rotates spontaneously in the ion diamagnetic direction; positive limiter bias first reduces, then minimizes (producing a n...

Flux limiting for hyperbolic systems requires a careful generalization of the design principles and algorithms introduced in the context of scalar conservation laws. In this chapter, we develop FCT-like algebraic flux correction schemes for the Euler equations of gas dynamics. In particular, we discuss the construction of artificial viscosity operators, the choice of variables to be limited, an...

The theory of flux-corrected transport (FCT) developed by Boris and Book [.I. Co~~pur. P~JLV. II (1973) 38; 18 (1975) 248; 20 (1976) 3971 is placed in a simple, generalized format, and a new algorithm for implementing the critical flux limiting stage in multidimensions without resort to time splitting is presented. The new flux limiting algorithm shows the use of FCT techniques in multidimensio...

In this work a new coupled level set volume tracking method is introduced. To advance the solution in time, a MUSCL-type method combined to a new flux limiter is used. It is shown that our discrete method has many interesting properties that make it suitable for problems where the tracking of a large number of regions is needed. A dedicated reconstruction algorithm for the level set reinizializ...

The penalization method is used to take account of obstacles, such as the limiter, in a tokamak. Because of the magnetic confinement of the plasma in a tokamak, the transport occurs essentially in the direction parallel to the magnetic field lines. We study a 1D nonlinear hyperbolic system as a simplified model of the plasma transport in the area close to the wall. A penalization which cuts the...