2008 13486 suppression of turbulence and travelling

Controlling the onset of turbulence by streamwise

Controlling the onset of turbulence by travelling waves:receptivity analysis 71 These results suggest that the proper turbulence-suppression design paradigm is that of disturbance attenuation or robust stabilization rather than modal stabilization. An alternative approach to feedback ow control relies on the understanding Drag Reduction by Spanwise Wall Oscillation in Wall May 17, 2012 · 30 August 2018 Flow, Turbulence and Combustion, Vol. 102, No. 3 Effect of shape modification on heat transfer and drag for fluid flow past a cam-shaped cylinder International Journal of Heat and Mass Transfer, Vol. 131

Drag reduction in turbulent flows along a cylinder by

The circumferential wall oscillation can lead to drag reduction due to the formation of a Stokes layer, but it may also result in centrifugal instability, which can enhance turbulence and increase drag. In the present work, the Reynolds number based on the reference friction velocity and the nominal thickness of the boundary layer is 272. How modern planes handle turbulence and make flying Yes, the Boeing 787 has similar gust suppression system as the Boeing 777 and will definitely provide a more comfortable ride in air turbulence. In fact, Boeing has engineered its new Boeing 787 Dreamliner to reduce light to moderate turbulence by up to two-thirds while the plane climbs to high altitudes. International Journal of Heat and Mass Transferwall turbulence behaviours, the turbulent heat transfer, and thermal structures under the control of the spanwise travelling wave. Three typical frequencies of the spanwise travelling wave, i.e., high-, mid-dle- and low-frequency, corresponding to the exciting periods at T+ = 25, 50 and 100, are investigated to

Inverse cascades, zonal jets and turbulence/transport

Anisotropic cascades in -plane turbulence 3 cascades cannot be isotropic. Let us produce turbulence near some k 0, surround it by a large non-dissipative area and dissipate at large k and at small k x and small k y. Fjortoftsargument separates the k-space into three non-intersecting sectors to which the energy, enstrophy and zonostrophy can cascade. Long-range transport of terrain-induced turbulence from with larger enhancement in turbulence by higher aspect ratio, while upstream there is a suppression of turbulence that does not appear to be sensitive to the terrain aspect ratio. Instanta-neous vorticity elds shows very detailed ow structures that resemble a multitude of eddy scales dynamically interacting Correspondence to:M. Katurji On the interplay between MHD instabilities and turbulent Oct 24, 2019 · (1) Turbulence spreading into the magnetic island, (2) there is a self-organized change in topology and turbulence in the magnetic island, (3) the flow is damped by a stochastic magnetic field, (4) the trigger mechanism for the MHD bursts, (5) MHD bursts have an impact on the ion velocity distribution and potential, and (6) turbulence exhausts

Publications about 'Navier-Stokes equations'

In Proceedings of the 2008 American Control Conference, Seattle, WA, pages 3064-3069, 2008. Keyword(s):Navier-Stokes equations, Incompressible fluids, Input-output analysis, Descriptor systems, Distributed systems theory. [bibtex-entry] R. Moarref and M. R. Jovanovic. On using the streamwise traveling waves for variance suppression in channel Suppression of spiral wave and turbulence by using Aug 15, 2009 · In the numerical simulation, the control area lies in 125 < i < 131, 0 < j < 6, and the whole media is discretized into 256 × 256 sites.In Fig. 6, the evolution of the stable rotating spiral wave is plotted, in Fig. 7, suppression of the meandering spiral wave is shown without spatiotemporal noise, in Fig. 8, the spatiotemporal noise is added to the whole media and the evolution of the Suppression of the Spiral Wave and Turbulence in the Jul 17, 2008 · Periodical forcing is used to control the spiral wave and turbulence in the modified Fithzhugh-Nagumo equation (MFHNe) when excitability is changed. The decisive parameter of (MFHNe), which describes the ratio of time scales of the fast activator u and the slow inhibitor variable v , is supposed to increase linearly to simulate the

Turbulent Boundary-Layer Control by Means of Spanwise

May 17, 2012 · Turbulence suppression in channel flows by small amplitude transverse wall oscillations Physics of Fluids, Vol. 20, No. 1 Turbulent drag reduction Suppression of turbulence and travelling waves in a Aug 01, 2020 · As the suppression of turbulence leads to severe heat transfer deterioration, this is an important and undesirable phenomenon in both heating and cooling applications. Our direct numerical simulations (DNS) show that under certain heating conditions, measured by the buoyancy parameter $C$, shear turbulence may either be completely laminarised or transitions to a relatively quiescent