Power minimisation in branched fluidic networks has gained significant attention biology and engineering. The optimal network is defined by channel radii that minimise the sum of viscous dissipation volumetric energetic cost fluid. For limit cases including laminar flows, high Reynolds number turbulence, or smooth approximations, solutions are known. However, no single optimisation approach captures these cases. Furthermore, realistic exhibit intermediate points parameter space can hardly be...

Numerical simulations are widely used to study the behavior of suspension flows. Fully resolved simulations, in which detailed flow around individual particles is computed, accurate but computationally expensive. Unresolved methods reduce computational cost significantly by only resolving bulk and modeling small-scale particles. However, degree rather than computing field information affects predicted flows largely unknown. Here, we examine steady homogeneous regime simulating pressure drop...

Two working mechanisms of Nasal High-Flow Therapy (NHFT) are washout anatomical dead space and provision positive end-expiratory pressure (PEEP). The extent both depends on the respiration aerodynamics corresponding distribution: at end-expiration onset uniform indicates jet penetration length, level is PEEP. clinical problem that adequate measurements in patients presently impossible. In this study, respiratory distribution therefore measured 3D-printed anatomically correct upper-airway...

The problem of predicting the moments distribution bubble radius in bubbly flows is considered. particular case where oscillations occur due to a rapid (impulsive or step change) change pressure analyzed, and it mathematically shown that this case, inviscid reach stationary statistical equilibrium, whereby phase cancellations among bubbles with different sizes lead time-invariant values statistics. It also at may be computed using period-averaged place instantaneous one. For sufficiently...

We determine the size of argon clusters generated with a planar nozzle, based on optical measurements in conjunction theoretical modelling. Using quasi-one dimensional model for moments cluster distribution, we influence critical physical assumptions. These refer to surface tension depending presence thermal equilibrium, mass density clusters, and different methods growth rate radius. show that, despite strong variation predicted size, 〈N〉, liquid ratio, g, can be determined high...

We consider condensing flow with droplets that nucleate and grow, but do not slip respect to the surrounding gas phase. To compute local droplet size distribution, one could solve general dynamic equation fluid dynamics equations simultaneously. reduce overall computational effort of this procedure by roughly an order magnitude, we propose alternative procedure, in which is initially replaced moment complemented a closure assumption. The key notion field obtained from so-called method...

It is well-known that freely falling or rising objects and self-propelling bodies shed vorticity.It then a natural question to ask how define the forces (drag lift) experienced by body in terms of vorticity distribution surrounding fluid normal velocity surface, since these uniquely.In this paper we outline answer given Burgers an almost forgotten from 1920, point at close relationship Burgers's ideas matters with those Sir James Lighthill.The connection more recent work Kambe Howe...

We investigate high-order harmonic generation (HHG) from noble gas clusters in a supersonic jet. To identify the contribution of versus that monomers, we measure output over broad range total atomic number density jet (from 3×1016 to 3 × 1018 ) at two different reservoir temperatures (303 and 363 K). For first time evaluation yield such measurements, variation liquid mass fraction, g, pressure temperature is taken into consideration, which determine, reliably consistently, be below 20%...

The kinetic equation (KE) and its first- second-order approximations, the general dynamic (GDE), Fokker–Planck (FPE), respectively, have been evaluated based on (a) their equilibrium distributions, (b) a nucleation pulse experiment, (c) an expanding nozzle flow. Large differences are observed between distributions of FPE KE, whereas GDE does not distribution at all. For good agreement is found FPE, due to quasisteady nucleation. condensing flow, difference KE large, although relevant flow...

Liquid layer thickness dependence of 515 nm, 7 picosecond pulsed laser ablation stainless steel 304 and silicon is analyzed. Ablated crater volume diameter are compared to ablated craters in ambient air by means a novel, objective numerical procedure. While under water found be more efficient terms removed material per pulse than air, an opposite trend for 304. For both materials, the efficiently drops when liquid decreased 1 milimeter. A probable reason efficiency drop persistent bubble formation.

Purpose: Contemporary diagnostic modalities, including contrast-enhanced computed tomography (CTA) and duplex ultrasound, have been insufficiently able to predict endograft thrombosis. This study introduces an implementation of image-based computational fluid dynamics (CFD), by exemplification with 4 patients treated for occlusive disease the superficial femoral artery (SFA). The potential personalized CFD predicting thrombosis is investigated. Materials Methods: Four endografts occluded SFA...

The motion of heavy particles in potential vortex flows on the unit disk is investigated theoretically and numerically. Configurations with one two vortices are considered. In both cases, each follows a regular path disk. one-vortex case, it shown that small, may accumulate elliptic regions flow, counter-rotating respect to vortex. When particle Stokes number exceeds threshold depending configuration, all expelled from circular domain. A stability criterion for accumulation derived...

The motion of small heavy particles near a helical vortex filament in incompressible flow is investigated. Both the configurations free space and concentric pipe are considered, corresponding helically symmetric velocity fields expressed terms stream function. Particle assumed to be driven by Stokes drag, independent from particles. Numerical results show that may attracted trajectories. stability these attraction trajectories demonstrated linear analysis. In addition, correlation between...

In this paper, the effects of an oscillatory entrainment speed on film thickness in elasto-hydrodynamically lubricated circular contact operating piezo-viscous regime as predicted by a conventional elasto-hydrodynamic lubrication model are described detail. The relative variation centreline mainly depends two dimensionless parameters: velocity amplitude and frequency. For small to moderate values frequency, results can be accurately through simplified ‘engineering approach’: propagation...

It is proved that two different and independently derived integral representations of droplet size distribution moments encountered in the literature are equivalent and, moreover, consistent with general dynamic equation governs function. One these consists an over radius while other representation time. The proof based on analytical solution absence coagulation but presence both growth nucleation. explicit radius, which contrast where solutions presented along characteristics. This...

We propose a computationally efficient method for the calculation of binary cluster size distribution. This is based on phase path analysis algorithm, which was originally derived single-component condensation. extend this by constructing general dynamic equation, introduces clusters at point in two component n1,n2-space. The location source determined Gibbs free energy formation and impingement rates constituents. resulting model describes distribution along line solution equation compared...

Purpose – The purpose of this paper is to create a computationally efficient reduced model (RM) for the moments droplet size distribution (DSD) in condensing flow. Design/methodology/approach kinetic equation (KE) exactly describes time dependence DSD and can be regarded as most rigorous representation system with condensation. Because typical wide range size, KE requires excessive computational not attractive practical applications. To reduce overall efforts, novel set moment equations,...

Spirometry is a gold standard to assess lung function, and identify respiratory impairments seen in obstructive diseases. The method used for periodic monitoring, but it only provides snapshot information, requires forceful exhalation which associated with limited reliability repeatability. Several studies indicate that tidal flow-volume curves measured by pneumotachography or plethysmography can also be function. These methods avoid the forced manoeuvre, are complex set up sensitive...

The present study is dealing with the analytical modelling of sound transmission through turbomachinery stators. Two-dimensional cascade models are applied in combination a newly proposed impedance model to account for effect flow deflection on propagation acoustic modes annular ducts. Further, two different approaches calculation 3D mode using 2D used. methods allow consideration vane twist and scattering w.r.t. radial order. results obtained compared outcome numerical calculations several...

Combining preoperative angiography findings with intraoperative transit time flow measurements (TTFM) may improve patency of coronary artery bypass grafts. Nevertheless, graft might be impaired by native based on the severity stenoses, inferior long-term outcomes. This study investigates impact left anterior descending (LAD) stenosis competitive measured in internal mammary (LIMA) grafts during off-pump grafting.