Showing papers by "Eli Turkel published in 1986"
TL;DR: In this paper, a finite difference for elastic waves is introduced and the model is based on the first order system of equations for the velocities and stresses of the elastic wave and is tested on a series of examples including the Lamb problem, scattering from plane interf aces and scattering from a fluid-elastic interface.
Abstract: A finite difference for elastic waves is introduced. The model is based on the first order system of equations for the velocities and stresses. The differencing is fourth order accurate on the spatial derivatives and second order accurate in time. The model is tested on a series of examples including the Lamb problem, scattering from plane interf aces and scattering from a fluid-elastic interface. The scheme is shown to be effective for these problems. The accuracy and stability is insensitive to the Poisson ratio. For the class of problems considered here it is found that the fourth order scheme requires for two-thirds to one-half the resolution of a typical second order scheme to give comparable accuracy.
182 citations
TL;DR: The stability properties of some improved accurate schemes are analyzed and it is shown that they also allow for larger time steps when Runge-Kutta type methods are used to advance in time.
62 citations
TL;DR: The concept of active control of growing disturbances in an unstable compressible flow by using time periodic, localized surface heating is studied numerically in this article, where simulations are calculated by a fourth-order accurate solution of the compressible, laminar Navier-Stokes equations.
Abstract: The concept of active control of growing disturbances in an unstable compressible flow by using time periodic, localized surface heating is studied numerically. The simulations are calculated by a fourth-order accurate solution of the compressible, laminar Navier-Stokes equations. Fourth-order accuracy is particularly important for this problem because the solution must be computed over many wavelengths. The numerical results demonstrate the growth of an initially small fluctuation into the nonlinear regime where a local breakdown into smaller scale disturbances can be observed. It is shown that periodic surface heating over a small strip can reduce the level of the fluctuation provided that the phase of the heating current is properly chosen.
37 citations
TL;DR: In this article, the fluctuating field of a jet excited by transient mass injection is simulated numerically and the model is developed by expanding the state vector as a mean state plus a fluctuating state.
21 citations
TL;DR: A pseudo-time method is introduced to integrate the compressible Navier-Stokes equations to a steady state and it is shown that for a simple heat equation that this is just a renormalization of the time.
11 citations
TL;DR: In this paper, the diffusion and transport of a fully collisional plasma across a strong magnetic field in a bounded domain are analyzed, and the conditions under which the system evolves into an equilibrium are examined.
Abstract: The equations governing the diffusion and transport of a fully collisional plasma across a strong magnetic field in a bounded domain are analyzed. Following a relatively short relaxation time, the diffusion exhibits universal properties independent of the choice of initial data. Mathematically this appears as a time asymptotic solution which is space‐time separable. The temporal decay rate is a nonlinear eigenvalue which is found via the solution of a related eigenvalue problem. This determines the spatial distribution of both the particle density and the pressure. Some of the transport effects caused by Bremsstrahlung radiation, particle, and heat injection are considered, and the conditions under which the system evolves into an equilibrium are examined.
4 citations
1 citations
01 Dec 1986
TL;DR: A finite-volume scheme for numerical integration of the Euler equations was extended to allow solution of the thin-layer Navier-Stokes equations in two and three dimensions and has yielded an efficient program for vector processors.
Abstract: A finite-volume scheme for numerical integration of the Euler equations was extended to allow solution of the thin-layer Navier-Stokes equations in two and three dimensions. The extended algorithm, which is based on a class of four-stage Runge-Kutta time-stepping schemes, was made numerically efficient through the following convergence acceleration technique: (1) local time stepping, (2) enthalpy damping, and (3) residual smoothing. Also, the high degree of vectorization possible with the algorithm has yielded an efficient program for vector processors. The scheme was evaluated by solving laminar and turbulent flows. Numerical results have compared well with either theoretical or other numerical solutions and/or experimental data.