The space-time conservation element and solution element (CE/SE) method is used to solve the conservation law form of the compressible axisymmetric Navier-Stokes equations. The equations are time marched to predict the unsteady flow and the near-field screech tone noise issuing from an underexpanded circular jet. The CE/SE method uses an unstructured grid based data structure. The unstructured ...

The pulsed flow about a circular non-centred orifice inside a cylindrical duct is analysed to obtain insight into the basic three-dimensional vortex dynamics that may be expected behind natural cardiac valves. The problem is approached by a highresolution numerical simulation. Results show how a small finite eccentricity generates a fully three-dimensional vortex wake that evolves quite differe...

Synthetic jets have been an area of interest in the recent years with constantly increasing industrial demand. Application areas are widespread and a strong focus is put on boundary layer control as well as on mixing enhancement. A synthetic jet has been studied using physical experiments involving high-speed camera footage and smoke visualisation. Additionally, threedimensional transient numer...

The effects of swirl and vaporization on droplet dispersion are investigated in the near region of a two-phase, swirling, heated jet. Simulations are based on the numerical solution of time-dependent, axisymmetric gas-phase equations.Droplets’ trajectories are tracked byusingaLagrangianapproach.Forall of the swirl cases investigated, the droplet dispersion exhibits a nonmonotonic behavior, with...

We have performed high-resolution 3D simulations of relativistic jets with beam flow Lorentz factors up to 7, a spatial resolution of 8 cells per beam radius, and for up to 75 normalized time units to study the morphology and dynamics of 3D relativistic jets. Our simulations show that the coherent fast backflows found in axisymmetric models are not present in 3D models. We further find that whe...

We present a new numerical method to simulate the time evolution of axisymmetric nonlinear waves on the surface of a ferrofluid jet. It is based on the reduction of this problem to a lower-dimensional computation involving surface variables alone. To do so, we describe the associated Dirichlet–Neumann operator in terms of a Taylor series expansion where each term can be efficiently computed by ...

In this investigation our objective is 1) to compare the similitude between an unsteady, two-dimensional (axisymmetric), partially premixed  ame and an analogous steady, partially premixed  amelet to determine if state relationshipsin terms ofamodiŽ ed conserved scalar applyand2) to investigate amestructure interactionsbetween the various reaction zones contained in partially premixed  ames...

Using an analogy with an Ising-like spin model, we define microcanonical measures for the dynamics of three dimensional (3D) axisymmetric turbulent flow in a Taylor-Couette geometry. We compute the relevant physical quantities and argue that axisymmetry induces a large scale organization in turbulent flows. We show that there exists a low energy, low temperature regime, for which the orthoradia...

The dynamical effects of magnetic fields in models of radiative, Herbig-Haro (HH) jets have been studied in a number of papers. For example, magnetized, radiative jets from variable sources have been studied with axisymmetric and 3D numerical simulations. In this paper, we present an analytic model describing the effect of a toroidal magnetic field on the internal working surfaces that result f...

We consider the problem of attitude and angular velocity stabilization of a rigid spacecraft subject to a single actuator failure. Only two pairs of gas jet actuators are available to perform the control objectives. Various controllers have been proposed for this problem in the case that the spacecraft is axisymmetric about one of its axis. In this paper the spacecraft under consideration is a ...