We introduce a cellular automaton model coupled with a transport equation for flows on graphs. The direction of the flow is described by a switching process where the switching probability dynamically changes according to the value of the transported quantity in the neighboring cells. A motivation is pedestrian dynamics during panic situations in a small corridor where the propagation of people...

We derive the energy spectrum in wave-number-frequency space for turbulent flows based on Kraichnan's idealized random sweeping hypothesis with additional mean flow, which yields the instantaneous energy spectrum multiplied by a Gaussian frequency distribution. The model spectrum has two adjustable parameters, the mean flow velocity and the sweeping velocity, and has the property that the power...

Sweeping jets are oscillating generated by fluidic oscillators, i.e., devices designed to produce an oscillation of the flow without use any moving parts (Raghu, 2013). A typical configuration such consists expansion chamber connected a high-pressure supply via converging nozzle and provided with feedback channels. The motion in is triggered inherent instability sustained rate across Recently, ...

An elliptic model for space-time correlations in turbulent shear flows is proposed based on a second order approximation to the iso-correlation contours, while Taylor's hypothesis implies a first-order approximation. It is shown that the space-time correlations are mainly determined by their space correlations and the convection and sweeping velocities. This model accommodates two extreme cases...

Space-time correlations or Eulerian two-point two-time correlations of fluctuating velocities are analytically and numerically investigated in turbulent shear flows. An elliptic model for the space-time correlations in the inertial range is developed from the similarity assumptions on the isocorrelation contours: they share a uniform preference direction and a constant aspect ratio. The similar...

In this paper, we present a high-order weighted essentially non-oscillatory (WENO) scheme, coupled with a high-order fast sweeping method, for solving a dynamic continuum model for bidirectional flow. We first review the dynamic continuum model for bi-directional flow. This model is composed of a coupled system of a conservation law and an Eikonal equation. Then we present the first-order Lax-F...

Analysis of published depth-kymography data [George, de Mul, Qiu, Rakhorst, and Schutte (2008). Phys. Med. Biol. 53, 2667-2675] shows that, for the subject studied, the flow due to the longitudinal sweeping motion of the vocal folds contributes several percent of a typical acoustic flow at the larynx. This sweeping flow is a maximum when the glottis is closed. This observation suggests that ass...

Nonlinear straining and random sweeping spatiotemporal decorrelation properties, originally introduced as the main processes for turbulent fluctuations decorrelation in usual fluid flows, have been observed experimentally in anisotropic electroconvective turbulence generated in a nematic liquid crystal under the action of an external oscillating electric field. A transition between both process...

We report an experimental study of the temperature space-time cross-correlation function, C{T}(r,τ), in the central region of turbulent Rayleigh-Bénard convection. The measured C{T}(r,τ) is found to have the scaling form C{T}(r{E},0), where r{E}=[r² +(Vτ)²]¹/² with V being the rms velocity at the center of the convection cell. The experiment confirms the theory by He et al. [Phys. Rev. E 73, 05...