Parallelization of the algebraic ctitious domain method is considered for solving Neumann boundary value problems with variable coeecients. The resulting method is applied to the parallel solution of the subsonic full potential ow problem which is linearized by the Newton method. Good scalability of the method is demonstrated in Cray T3E distributed memory parallel computer using MPI in communi...

A global noise reduction of a high-subsonic jet is achieved by experimental use of an impinging microjets system. The microjet velocity relative to the main jet velocity, the longitudinal distance of injection and the number of microjets are the three parameters examined in order to obtain the maximum noise reduction. This optimized microjet configuration is obtained by a balance between low-fr...

An analysis of the effect of local preconditioning on boundary conditions for the subsonic, one-dimensional Eulcr equations is prcscntcd. Dccay rates for the cigcnmodcs of the initial boundary valuc problem arc determined for different boundary conditions. Ricmann invariant boundary conditions based on the unprcconditioncd Eulcr cquations are shown to bc reflective with preconditioning, and, at...

suMM.4RY _______________________________________________ ~N~ODrC~OX ------------------------------------------sYmoM -----------------------------------------------I. PEEU~IIXART eONsIDEE.iTIOXS-------------------------2. 13ALCULATIOXOF THE LIMITS OF STABILITY OF L.WIX.AR BOUNDARYLAYER IFi AVISCOIJSf20XDCCTIVEGas. _______ 3. DESTABILIZINGIXFLUEXCEOF VISCOSITY AT T’ERY LARGE REYNOLDS XUMBERS; EXT...

This paper is devoted to the study of a transonic shock in threedimensional steady compressible flow passing a duct with a general section. The flow is described by the steady full Euler system, which is purely hyperbolic in the supersonic region and is of elliptic-hyperbolic type in the subsonic region. The upstream flow at the entrance of the duct is a uniform supersonic one adding a three-di...

We provide a first look at the results of the Herschel Gould Belt survey toward the IC 5146 molecular cloud and present a preliminary analysis of the filamentary structure in this region. The column density map, derived from our 70–500 μm Herschel data, reveals a complex network of filaments and confirms that these filaments are the main birth sites of prestellar cores. We analyze the column de...

D of point P in a meridian plane for an accelerating, decelerating and accelerating supersonic speed starting from rest at = 0. The subsonic and supersonic intervals are 0; 1) and (1; 5] with the deceleration in (1:7; 3:05). The critical curve J has a local maximum at point K 1 , a minimum at K 2 and then a maximum at K 3. The curve J partitions D into

We establish the existence and stability of multidimensional transonic flows with transonic shocks through an infinite nozzle of arbitrary cross-sections, including a slowly varying de Lavel nozzle. The transonic flow is governed by the inviscid steady potential flow equation with supersonic upstream flow at the entrance, uniform subsonic downstream flow at the infinite exit, and the slip bound...

Using time-dependent linear perturbation theory, we evaluate the dynamical friction force on a massive perturber Mp traveling at velocity V through a uniform gaseous medium of density ρ0 and sound speed cs. This drag force acts in the direction −V̂ , and arises from the gravitational attraction between the perturber and its wake in the ambient medium. For supersonic motion (M ≡ V/cs > 1), the en...