We propose a flexible exchange format for ω-automata, as typically used in formal verification, and implement support for it in a range of established tools. Our aim is to simplify the interaction of tools, helping the research community to build upon other people’s work. A key feature of the format is the use of very generic acceptance conditions, specified by Boolean combinations of acceptanc...

Flow in a gas-lift digester with a central draft-tube was investigated using computational fluid dynamics (CFD) and different turbulence closure models. The k-ω Shear-Stress-Transport (SST), Renormalization-Group (RNG) k-∊, Linear Reynolds-Stress-Model (RSM) and Transition-SST models were tested for a gas-lift loop reactor under Newtonian flow conditions validated against published experimental...

An intermittency transport equation for RANS modeling, formulated in local variables, is extended for roughness-induced transition. To predict roughness effects in the fully turbulent boundary layer, published boundary conditions for k and ω are used. They depend on the equivalent sand-grain roughness height, and account for the effective displacement of wall distance origin. Similarly in our a...

In this work, we investigate the flow field around speed skating helmets and their associated aerodynamic drag by means of computational fluid dynamics (CFD) simulations. An existing helmet frequently used in competition was taken as a baseline. Six additional designs, well bare-head configuration, were analysed. All numerical simulations performed via 3D RANS using SST k-ω turbulence model. Th...

We study the vertical settling of solid bodies in a turbulent protoplanetary disc. We consider the situation when the coupling to the gas is weak or equivalently when the particle stopping time τst due to friction with the gas is long compared to the orbital timescale Ω. An analytical model, which takes into account the stochastic nature of the sedimentation process using a Fokker-Planck equati...

An improved k-ω turbulence model for viscoelastic fluids is developed to predict turbulent flows, with polymeric solutions described by the finitely extensible nonlinear elastic-Peterlin constitutive model. The tested against a wide range of direct numerical simulation data in fully-developed channel flow, different rheological parameter combinations, and can all regimes drag reduction (low, in...

Abstract The mesh significantly influences the quality of numerical results in computational fluid dynamics (CFD) problems due to its correlation with turbulence models. In present paper a structured was generated using Gmsh and two semi-structured meshes were snappyHexMesh determine suitable distribution for simulating unsteady cavitation around plane convex hydrofoil. simulation conducted by ...

Wind flow on and around buildings attains more importance among architectures, builders, urban planners, structural engineers, wind engineers. tunnel experiments assessments of full-scale are expensive complex in varied terrain conditions. Hence, flows extensively assessed using Computational Fluid Dynamics (CFD). By following the turbulence parameters, CFD models create atmospheric environment...