The dynamics of dense finite-size particles in vertical channel flows Newtonian and viscoelastic carrier fluids are examined using particle resolved simulations. Comparison to neutrally buoyant the same configuration highlights effect settling. volume fraction is $5\%$, a gravity field acts counter flow direction. Despite modest density ratio ($\rho_r = 1.15$), qualitative changes arise due rel...

Energy-containing eddies (energy-eddies) are the elementary structures of wall turbulence that carry most kinetic energy and momentum. Despite consensus energy-eddies can self-sustain at each relevant length scale, their precise origin spatial evolution currently not well understood. In this study, we examine by quenching them inflow a turbulent channel flow. Our study shows involved in cascade...

A large eddy simulation (LES) study of the flow around a 1/4 scale squareback Ahmed body at ReH=33,333 is presented. The consists both wall-resolved (WRLES) and wall-modelled (WMLES) simulations, investigates bimodal switching wake between different horizontal positions. Within non-dimensional time-window 1050 convective units, WRLES WMLES for which only near-wall region turbulent boundary laye...

In hypersonic boundary layers, Mack modes play a crucial role in flow instability, whose secondary instability is hot research topic. Since flight vehicles will probably work under high-stagnation temperature conditions, which significantly affect the aerodynamic heating calculation and aero-thermal protection design of vehicles, it necessary to compare primary instabilities layers that Boeing/...

Estimation of the initial state turbulent channel flow from limited data is investigated using an adjoint-variational approach. The are generated a reference direct numerical simulation (DNS) which sub-sampled at different spatiotemporal resolutions. When velocity 1/4096 resolution DNS, correlation coefficient between true and estimated exceeds 99 percent. robustness algorithm to observation no...

The present paper simplifies the naturally formed dunes (riverbeds) as large-scale three-dimensional staggered wavy walls to investigate features of accompanying secondary flows and streamwise vortices via large-eddy simulation. A comparison between swirling strength mean velocities suggests where a flow induces upwash or downwash motions. Moreover, we propose pseudo-convex wall mechanism inter...

We consider the three-dimensional Poiseuille problem of a viscous incompressible uid ow between parallel plates. The ows under investigation are assumed to be traveling waves in streamwise direction with spatial periodicity 2==. In spanwise direction they are assumed to be uniformly close to the basic ow which enables us to use the spatial center{manifold reduction, where the spanwise variable ...

OBJECTIVES To describe the current use of airway clearance techniques among people with cystic fibrosis (CF) in the UK, and the baseline characteristics for users of different airway clearance techniques. DESIGN Analysis of the UK CF Registry 2011 data. SETTING AND PARTICIPANTS All people with CF in the UK aged ≥11 years (n=6372). RESULTS Of the 6372 people on the UK CF registry in 2011, ...