Abstract Decaying grid turbulence is considered at low Reynolds number (Rλ ~ 50) for different initial conditions. Three different grid geometries are used. Heat is injected via a mandoline at a distance of 1.5 M from the grid. The amount of heating is such that temperature may be treated as a passive scalar. A small contraction (1.36:1) is added at a distance of 11M downstream of the grid. The...

It is often desirable to study turbulent flows at steady state even if the flow has no inherent source of turbulence kinetic energy. Doing so requires a forcing schema, and various methods applicable to laboratory experiments or numerical simulations have been studied extensively for turbulence that is isotropic and homogeneous in three dimensions. A review of existing schemata for simulations ...

1 Abstract In this paper we discuss the dynamical features of intermittent fluctuations in homogeneous shear flow turbulence. In this flow the energy cascade is strongly modified by the production of turbulent kinetic energy related to the presence of vortical structures induced by the shear. By using direct numerical simulations, we show that the refined Kolmogorov similarity is broken and a n...

BACKGROUND Measurement of intracardiac kinetic energy (KE) provides new insights into cardiac hemodynamics and may improve assessment and understanding of heart failure. We therefore aimed to investigate left ventricular (LV) KE time curves in patients with heart failure and in controls. METHODS Patients with heart failure (n = 29, NYHA class I-IV) and controls (n = 12) underwent cardiovascul...

The basic science of turbulence has been known for many years, yet the knowledge has hardly become a part of operational aviation turbulence forecasting. The history of turbulence forecasting, which has primarily concentrated at elevations above the boundary layer, has been an amalgamation of empirical rules of thumb and forecaster intuition, not of strong theory and conceptual models. Turbulen...

Three-electron kinetic energy and electron–nucleus interaction integrals arising in Hylleraas–configuration interaction (Hy–CI) calculations are discussed. We show that the electron–nucleus interaction operators introduce no new integral complications and that the kinetic energy operators lead to integrals which have much in common with electron interaction integrals treated in the first paper ...

Molecular binding in post-Kohn-Sham orbital-free DFT is investigated, using noninteracting kinetic energy functionals that satisfy the uniform electron gas condition and which are inhomogeneous under density scaling. A parameter is introduced that quantifies binding, and a series of functionals are determined from fits to near-exact effective homogeneities and/or Kohn-Sham noninteracting kineti...

Light nuclei at room temperature and below exhibit a kinetic energy which significantly deviates from the predictions of classical statistical mechanics. This quantum kinetic energy is responsible for a wide variety of isotope effects of interest in fields ranging from chemistry to climatology. It also furnishes the second moment of the nuclear momentum distribution, which contains subtle infor...

This paper investigates the efficiency of a 2-period gait from the kinetic energy view-point. First, we formulate a steady 2-period gait for a compass-like bipedal robot by using a simple recurrence formula for the kinetic energy of an asymmetric rimless wheel. Second, we theoretically show that, in the case that the mean value of the hip angle is constant, the generated 2-period steady gait is...

We solve for the motion of charged particles in a helical time-periodic ABC (Arnold-Beltrami-Childress) magnetic field. The magnetic field lines of a stationary ABC field with coefficients A=B=C=1 are chaotic, and we show that the motion of a charged particle in such a field is also chaotic at late times with positive Lyapunov exponent. We further show that in time-periodic ABC fields, the kine...