Abstract In the frame of RETALT (RETro propulsion Assisted Landing Technologies) project, aerodynamics reusable launch vehicles reentering atmosphere and descending landing with aid retro are studied. particular, series wind tunnel tests performed to assess aerodynamic properties such a vehicle in various flight phases from hypersonic supersonic re-entry down subsonic conditions at touch down. ...

In this short note we study the model of subsonic detonation introduced by Sivashinsky. The model is described by the system of reaction-diffusion equations involving temperature, pressure and concentration of deficient reactant. It is shown that initial data with small support lead to quenching (decay of solution). In contrast, initial data with support large enough lead to propagation with fi...

Analysis of the aerodynamic forces acting on baseball pitches from major league games reveals a large variance in the measured coefficients of lift and drag. We have examined possible explanations for this effect and found that, while uncertainties introduced by measurement error and the method of reporting major league pitch trajectories do explain some of the spread, the reasons for the large...

The location of the plasma sheath edge, where quasineutrality is broken, is rigorously derived by using a kinetic description of the plasma. It is shown that sheaths can exist with arbitrarily small ion velocity at the sheath edge, thus violating the Bohm criterion, V(i)=c(s) at the sheath edge. Bohm's criterion is recovered in the case of large enough ion current through the wall, and it is fo...

The subsonic expansion of bubbles in a strongly first-order electroweak phase transition is a convenient scenario for electroweak baryogenesis. For most extensions of the Standard Model, stationary subsonic solutions (i.e., deflagrations) exist for the propagation of phase transition fronts. However, deflagrations are known to be hydrodynamically unstable for wall velocities below a certain cri...

A numerical analysis is made of the inviscid flow produced by a cylinder which accelerates from a state of rest to a constant, subsonic speed in a gas at rest. All features of the numerical solution are explained on physical grounds. Consequently, ways are suggested to computed steady subsonic lows around obstacles with a maximum accuracy and a minimum computational time. This research was supp...

We study the properties of a binary microcavity polariton superfluid coherently injected by two lasers at different momenta and energies. The crossover from the supersonic to the subsonic regime, where motion is frictionless, is described by evaluating the linear response of the system to a weak defect potential. We show that the coupling between the two components requires that either both com...

This article presents the boundary conditions for the problem of turbulent supersonic gas flow in a plane channel with a perpendicular injection jets. The non-reflection boundary conditions for direct modeling of compressible viscous gases are studied. A formulation using the NSCBC (NavierStocks characteristic boundary conditions) through boundaries is derived for the subsonic inflow and subson...

One contribution of 13 to a Theme Issue 'Aerodynamics, computers and the environment' .

Transonic aerodynamics is the focus of strong interest at the present time because it is known to encompass one of the most efficient regimes of flight. While current transport aircraft operate just below the speed of sound, more radical aerodynamic designs, such as R. T. Jones’ proposal for a yawed wing in [1], favor operation at low supersonic speeds in the range from Mach 1 to 1.3 (a regime ...