Asymptotic expansions for small Strouhal number, valid for arbitrary subsonic Mach number, are derived for the solution of a simple problem of the interaction between an acoustic wave, a jet flow and a pipe, based on Munt's [ l ] exact formal solution. These expansions relate to the pressure and velocity fluctuations in the jet flow and in the far field, and to the reflection coefficient, end-i...

Experimental investigations into the dynamics of cylindrical, laser-driven, high-Mach-number shocks are used to study the thermal cooling instability predicted to occur in astrophysical radiative blast waves. A streaked Schlieren technique measures the full blast-wave trajectory on a single-shot basis, which is key for observing shock velocity oscillations. Electron density profiles and deceler...

This paper experimentally investigates the acoustic behavior of a homogeneous porous material with a rigid frame (metallic foam) under grazing flow. The transmission coefficient shows an unusual oscillation over a particular range of frequencies which reports the presence of an unstable hydrodynamic wave that can exchange energy with the acoustic waves. This coupling of acoustic and hydrodynami...

Guided-wave optical biosensors are reviewed in this paper. Advantages related to optical technologies are presented and integrated architectures are investigated in detail. Main classes of bio receptors and the most attractive optical transduction mechanisms are discussed. The possibility to use Mach-Zehnder and Young interferometers, microdisk and microring resonators, surface plasmon resonanc...

Abstract. Exact one-dimensional steady flow equations for viscous, heat conducting calorically perfect gases were derived in terms of a velocity potential. These nonlinear differential equations were integrated numerically thus predicting detailed variation of thermodynamic and flow properties through the normal steady compression shock waves for an entire range of ratios of secondary and prima...

We give a comparison of various di erential cross{section models for a classical polyatomic gas for a homogeneous relaxation problem and the shock wave pro les at Mach numbers 1.71 and 12.9. Besides the standard Borgnakke{Larsen model and its generalization to an energy dependent coe cient to control the amount of rotationally elastic and completely inelastic collision, we discuss some new mode...

Use of conventional scattering solvers for the problem of sound diffraction in the presence of a mean flow requires the use of variable transformations that reduce the wave equation to its canonical form. This enables the assessment of the mean-flow impact on the radiation of the isolated source as well as its diffraction by an object. Applications include the shielding of propulsion noise sour...