Mixing of materials by small scale turbulent motion is a critical element of many flow systems of interest in engineering, geophysics, and astrophysics. Numerical simulation plays a crucial role and turbulent mixing predictability is a major concern. Small scale resolution requirements focus typically on those of continuum fluid mechanics described by Navier–Stokes (NS) equations; different req...

Computational fluid dynamics (CFD) is increasingly used to simulate complex industrial systems. Most CFD analysis relies on the Reynolds-averaged Navier-Stokes (RANS) approach and traditional two-equation turbulence models. Higher-fidelity approaches to the simulation of turbulence such as wallresolved large eddy simulation (LES) and direct numerical simulation (DNS) remain limited to smaller a...

Abstract Good understanding of micro-scale urban-wind phenomena is needed for optimizing power generation capabilities building-integrated wind turbines and safety futuristic urban transport involving drones. The current work involves development a multiscale methodology obtaining fields in an landscape. multi-scale coupling three models operating on different scales namely operational meso-sca...

This paper focusses on three main numerical methods, i.e., the Reynolds-Averaged Navier-Stokes (RANS), Large Eddy Simulation (LES), and Direct Numerical (DNS) methods. The formulation variation of different RANS methods are evaluated. advantage disadvantage models to characterize turbulent flows discussed. progress LES with subgrid scale is presented. Special attention paid inflow boundary cond...

Stratified flows are prevalent in indoor and outdoor environments. To predict these flows, this investigation evaluated the performance of seven turbulence models by comparing the simulation results with the experimental data of both weakly and strongly stratified jets. The models tested included six Reynolds-Averaged Navier-Stokes (RANS) models and one Large Eddy Simulation (LES) model. The ve...

An entirely new approach to the large-eddy simulation (LES) of high-speed compressible turbulent flows is presented. Subgrid scale stress models are proposed that are dimensionless functions of the computational mesh size times a Reynolds stress model. This allows a DNS to go continuously to an LES and then a Reynolds-averaged Navier-Stokes (RANS) computation as the mesh becomes successively mo...

Optimal control of enclosed environment requires detailed information of air distribution that could be obtained by numerically solving Navier-Stokes equations with a suitable turbulence model. This investigation evaluated the performance of eight turbulence models for transient airflow in enclosed environment using experimental data obtained in a room. The study used the room to create three c...

The original (delayed) detached-eddy simulation ((D)DES), a widely used and efficient hybrid turbulence method, is confronted with some flaws containing grid-induced separation (GIS), log-layer mismatch (LLM), slow RANS-LES transition. A novel model, namely production-limited eddy (PLES), depleting the production through introducing subarid-scale viscosity proposed. data of zero-pressure gradie...