This article reviews state-of-the-art adaptive, multiresolution wavelet methodologies for modeling and simulation of turbulent flows with various examples. Different numerical methods solving the Navier-Stokes equations in adaptive bases are described. We summarize coherent vortex extraction methodologies, which utilize efficient decomposition into space-scale contributions, present a hierarchy wavelet-based turbulence models. Perspectives computing industrially relevant also given.

We decompose turbulent flows into two orthogonal parts: a coherent, inhomogeneous, non-Gaussian component and an incoherent, homogeneous, Gaussian component. The components have different probability distributions correlations, hence scaling laws. This separation coherent vortices incoherent background flow is done for each realization before averaging the results calculating next time step. To perform this decomposition we developed nonlinear scheme based on objective threshold defined in...

This Letter presents a wavelet technique for extracting coherent vortices from three-dimensional turbulent flows, which is applied to homogeneous isotropic flow at resolution N = 256(3). The reconstructed only 3%N coefficients that retain the vortex tubes, and 98.9% of energy with same k(-5/3) spectrum as total flow. In contrast, remaining 97%N correspond incoherent structureless, decorrelated, whose effect can therefore be modeled statistically.

Abstract Durch den radikalen Wechsel vom Verbundpartner Stahl zu Carbonstrukturen müssen die Anforderungen an Matrix völlig neu überdacht werden. Dieser Aufgabe widmete sich das Basisvorhaben B2 im Rahmen des Großprojekts Carbon Concrete Composite C 3 . Bei der konkreten Entwicklung und Umsetzung Bindemittel‐ Betonkonzepte standen Vorhaben eine langfristige Verfügbarkeit Ausgangsstoffe, ökologische wirtschaftliche Kriterien, Erreichen bestimmter Frisch‐ Festbetoneigenschaften sowie...

High-resolution numerical simulations of a tethered model bumblebee in forward flight are performed superimposing homogeneous isotropic turbulent fluctuations to the uniform inflow. Despite tremendous variation turbulence intensity, between 17% and 99% with respect mean flow, we do not find significant changes cycle-averaged aerodynamic forces, moments, or power when averaged over realizations, compared laminar inflow conditions. The variance measures, however, significantly increases...

The coherent vortex simulation (CVS) decomposes each realization of a turbulent flow into two orthogonal components: An organized and random incoherent flow. They both contribute to all scales in the inertial range, but exhibit different statistical behaviors. CVS decomposition is based on nonlinear filtering vorticity field, projected onto an orthonormal wavelet basis made compactly supported functions, computation induced velocity field using Biot–Savart’s relation. We apply it...

Coherent vortices are extracted from data obtained by direct numerical simulation (DNS) of three-dimensional homogeneous isotropic turbulence performed for different Taylor microscale Reynolds numbers, ranging Reλ=167 to 732, in order study their role with respect the flow intermittency. The wavelet-based extraction method assumes that coherent what remains after denoising, without requiring any template shape. Hypotheses only made on noise that, as simplest guess, is considered be additive,...

Surfaces of carbon fibre roving were modified by means a low temperature plasma treatment to improve their bonding with mineral fines; the latter serving as an inorganic coating for improved mechanical performance reinforcement in concrete matrices. Variation conditions, such gas composition and time, was accomplished establish polar groups on fibres prior contact suspension particles water. Subsequently, rovings implemented fine matrix pull-out assessed. Every resulted increased forces...

The question of the relative importance coherent structures and waves has for a long time attracted great deal interest in astrophysical plasma turbulence research, with more recent focus on kinetic scale dynamics. Here we utilize high-resolution observational simulation data to investigate nature emerging weakly collisional, turbulent plasma. Observational results are based situ solar wind measurements from Cluster Magnetospheric Multiscale (MMS) spacecraft, obtained an externally driven,...

The natural wind environment that volant insects encounter is unsteady and highly complex, posing significant flight-control stability challenges. It critical to understand the strategies employ safely navigate in environments. We combined experiments on free flying bumblebees with high-fidelity numerical simulations lower-order modeling identify mechanics mediate insect flight winds. trained fly upwind towards an artificial flower a tunnel under steady von Kármán street formed wake of...

We introduce FluSI, a fully parallel open source software package for pseudospectral simulations of three-dimensional flapping flight in viscous flows. It is freely available noncommercial use from GitHub (https://github.com/pseudospectators/FLUSI). The computational framework runs on high performance computers with distributed memory architectures. discretization the incompressible Navier--Stokes equations based Fourier method adaptive time stepping. complex varying geometry insects rigid...

This work investigates the behavior of impurities in edge plasma tokamaks using high-resolution numerical simulations based on Hasegawa–Wakatani equations. Specifically, it focuses inertial particles, which has not been extensively studied field physics. Our utilize one-way coupling a large number point model impurities. We observe that with Stokes (St), characterizes inertia particles being much less than one, such light closely track fluid flow without pronounced clustering. For...