Supersonic jets emit noise to the outside in form of Mach waves which are long, straight and have about equal angles. Experiments done by Oertel sen. visualized clearly these Mach waves and he publicized moreover that such Mach waves exist also inside the jet. Experimental and theoretical studies in the past did not allow a complete understanding of the phenomenon up to now, wherefore the need ...

The explosion of a Type Ia supernova (SNIa) begins as a turbulent flame deep within a 1.4 solar-mass white dwarf. Initially the burning happens in the flamelet regime where turbulence only serves to wrinkle and fold an essentially laminar burning front. However, as the star expands and the flame moves outwards, it encounters regions of lower density. At ∼ 2 × 10g cm, the flame transitions to a ...

The low Mach number limit for classical solutions of the full Navier-Stokes equations is here studied. The combined effects of large temperature variations and thermal conduction are taken into account. In particular, we consider general initial data. The equations lead to a singular problem whose linearized is not uniformly well-posed. Yet, it is proved that the solutions exist and are uniform...

We develop a low Mach number formulation of the hydrodynamic equations describing transport of mass and momentum in a multispecies mixture of incompressible miscible liquids at specified temperature and pressure that generalizes our prior work on ideal mixtures of ideal gases [K. In this formulation we combine and extend a number of existing descriptions of multispecies transport available in t...

The goal of this study is to develop an efficient numerical algorithm applicable to a wide range of compressible multicomponent flows, including nearly incompressible low Mach number flows, flows with strong shocks, multicomponent flows with high density ratios and interfacial physics, inviscid and viscous flows, as well as flows featuring combinations of these phenomena and various interaction...

Two semi-implicit methods based on the splitting of the Euler equations ux into uid and acoustic parts applied to low Mach number ows are presented. The rst method is based on the splitting of slow and fast eigenvalues of the jacobian matrix of the uxes and a semi-implicit scheme is constructed by introducing only the fast eigenvalues in the implicit matrices. The second method is based on the ...

The relationship between the compressible magnetohydrodynamic flows with low Mach number and the incompressible magnetohydrodynamic flows is investigated. More precisely, the convergence of weak solutions of the compressible isentropic viscous magnetohydrodynamic equations to the weak solutions of the incompressible viscous magnetohydrodynamic equations is proved as the density becomes constant...

Aleksandar Donev, ∗ Andy Nonaka, Yifei Sun, 3 Thomas G. Fai, Alejandro L. Garcia, and John B. Bell Courant Institute of Mathematical Sciences, New York University, New York, NY 10012 Center for Computational Science and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720 Leon H. Charney Division of Cardiology, Department of Medicine, New York University School of Medicine, N...

The effect of compressibility on the onset of nonhelical turbulent dynamo action is investigated using both direct simulations as well as simulations with shock-capturing viscosities, keeping however the regular magnetic diffusivity. It is found that the critical magnetic Reynolds number increases from about 35 in the subsonic regime to about 70 in the supersonic regime. Although the shock stru...