This paper presents the results of using high-order compact schemes with a high-order filter on multi-block domains. The Linearized Euler Equations (LEE) are solved on a uniform mesh for benchmark problems in one and two dimensions. Also a two dimensional mixing layer is solved by using LargeEddy Simulation (LES). Three different boundary schemes are compared. The results compare well with the ...

3 PMLs for the Euler System 5 3.1 PML for the advective wave equation . . . . . . . . . . . . . . . . . . . . . . . . . 6 3.2 First PML model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.3 PMLness of the first model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.4 Second PML model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....

We present an overview of the current state of detonation stability theory and discuss its implications for propulsion. The emphasis of the review is on the exact or asymptotic treatments of detonations, including various asymptotic limits that appear in the literature. The role that instability plays in practical detonation-based propulsion is of primary importance and is largely unexplored, h...

The paper I s a revlew of sound generatlon In turbulent shear flows. It emphasizes slmultaneous 0 calculatlon of the turbulent flow along wlth the ' h cr) resulting sound generatlon rather than the alternaI tlve acoustlc analogy approach. The first part of w the paper I s concerned wlth solld surface lnteractlon. The second part concentrates on the sound generated by turbulence Interacting wlth...

In these lecture notes, we discuss the goals of computational aeroacoustics (CAA) and the numerical techniques that have been developed to achieve them. We first survey the scientific and engineering issues that have motivated computational approaches to aeroacoustic problems over the past few decades, and define choices of flow model and numerical algorithms that are appropriate to the differi...

The need of aeroacoustically highefficient fans requires more detailed investigations of three dimensional effects and separated flow analysis. Comprehensive studies and code validation for fans have shown, that further development especially for the influence of sweep -is necessary. Therefore, two different Navier-Stokes Codes, a lifting surface code and a classical method for 3-D cascade flow...

The behavior of difference approximations of hyperbolic partial differential equations as time t -* oo is studied. The rate of convergence to steady state is analyzed theoretically and expe ¡mentally for the advection equation and the linearized Euler equations. The choice of difference formulas and boundary conditions strongly influences the rate of convergence in practical steady state calcul...

Wavelet transform has become a common tool for processing non-stationary signals in many different fields. The present paper reports review of some applications wavelet aeroacoustics with special emphasis on the analysis experimental data taken compressible jets. focus is three classes wavelet-based signal procedures: (i) conditional statistics; (ii) acoustic and hydrodynamic pressure separatio...

We study the asymptotic expansion of solutions to the linearized compressible Navier-Stokes equations with highly oscillatory forces in the half-plane with nonslip boundary conditions for small viscosity. The wave length of oscillations is assumed to be proportional to the square root of the viscosity. By means of asymptotic analysis, we deduce that the zero-viscosity limit of solutions satisfi...