This article outlines some of the principal issues in the development of numerical methods for the prediction of flows over aircraft and their use in the design process. These include the choice of an appropriate mathematical model, the design of shock-capturing algorithms, the treatment of complex geometric configurations, and shape modifications to optimize the aerodynamic performance.

Most recent extragalactic models of gamma-ray bursts consider the expansion of a relativistic blast wave, emanating from a solar-mass type progenitor, into the surrounding interstellar medium as the site for their activity. The popular perception is that the optical afterglows result from the external shock interface, while the prompt transient gamma-ray signal arises from multiple shocks inter...

We compute the impulse response of output to an aggregate monetary shock in a general equilibrium when firms set prices subject to a costly observation of the state and a menu cost. We study how the aggregate effects of a monetary shock depend on the relative size of these costs. We find that empirically reasonable observations costs increase the impact and the persistence of the output respons...

We investigate an angular variation of pressure at a laser-induced shock front in a liquid filled thin tube. We adopt the background-oriented schlieren (BOS) technique. This technique enables us to measure twoor three-dimensional pressure field in a small region with a simple setup. We obtain the spatiotemporal evolution of the pressure field thanks to an ultra high-speed video camera and a las...

The condition of linear instability for a converging cylindrical shock wave in an arbitrary inviscid medium is obtained. shape resulting front not changed significantly, but the restriction energy cumulation can be caused by exponential grows rotation behind front. correspondence with experimental and simulation data considered.

The Drosophila heat shock cognate gene 4 (hsc4), a member of the hsp70 gene family, encodes an abundant protein, hsc70, that is more similar to the constitutively expressed human protein than the Drosophila heat-inducible hsp70. Developmental expression revealed that hsc4 transcripts are enriched in cells active in endocytosis and those undergoing rapid growth and changes in shape.

Preservation of cell architecture under physically stressful conditions is a basic requirement for many biological processes and is critical for mechanosensory systems built to translate subtle changes in cell shape into changes in organism behaviour. A new study reveals how an extracellular protein--Spam--helps mechanosensory organs in the fruit fly to withstand the effects of the water loss t...

We present an investigation into the effect of the motion of a printed circuit board (PCB) on the response of a microelectromechanical system (MEMS) device to shock loads. A two-degrees-of-freedom model is used to model the motion of the PCB and the microstructure, which can be a beam or a plate. The mechanical shock is represented as a single point force impacting the PCB. The effects of the f...

We extend our previous studies of shock waves and shock-free solutions in thin accretion and winds in pseudo-Newtonian geometry to the case when the flow is two-dimensional and around a Kerr black hole. We present equations for fully general relativistic viscous transonic flows and classify the parameter space according to whether or not shocks form in an inviscid flow. We discuss the behaviors...

A new method for the design of waverider con-gurations with generalized shock geometries is presented. An arbitrary three-dimensional shock shape is speciied as input, and a cross-stream Euler marching procedure is used to deene the post-shock ow-eld. Unlike most previous studies, this approach allows for the use of nonaxisymmetric shock topologies with nonconstant shock strengths. The problem'...