Large eddy simulation (LES) of the atmospheric boundary layer (ABL) flow over complex terrain is presented with a validation using meteorological tower (met-tower) data through an improved neutral stability sampling approach. The proposed procedure includes condition based on most-likely occurrence time-periods ABL and reduces variabilities conditional wind statistics calculated at met-towers i...

Computational fluid dynamics using the Reynolds-averaged Navier–Stokes (RANS) remains most cost-effective approach to study wake flows and power losses in wind farms. The underlying assumptions associated with turbulence closures are biggest sources of errors uncertainties model predictions. This work aims quantify model-form RANS simulations farms at high Reynolds numbers under neutrally strat...

The Reynolds-averaged Navier–Stokes (RANS)-based method is a practical tool to provide rapid assessment of jet noise-reduction concepts. However, the RANS-based requires modeling assumptions represent noise generation and propagation, which often reduces predictive accuracy due model-form uncertainties. In this work, ensemble Kalman filter-based acoustic inversion introduced reduce uncertaintie...

Abstract Turbulence pervades most flows of engineering interest, and its prediction remains a challenge on both accuracy cost. One promising predictive approach that reduces cost combines large‐eddy simulation (LES) with based Reynolds averaged Navier–Stokes equations (RANS). This study presents method to overcome stability issues associated these hybrid LES‐RANS methods. The developed involves...

The corner separation in the high-loaded compressors deteriorates the aerodynamics and reduces the stable operating range. The flow pattern is further complicated with the interaction between the aperiodic corner separation and the periodically wake-shedding vortices. Accurate prediction of the corner separation is a challenge for the Reynolds-Averaged Navier–Stokes (RANS) method, which is base...

A novel method is proposed for blending RANS and VMS-LES approaches in a hybrid model. To this purpose, the ow variables are decomposed in a RANS part (i.e. the averaged ow eld), a correction part that takes into account the turbulent large-scale uctuations, and a third part made of the unresolved or SGS uctuations. The basic idea is to solve the RANS equations in the whole computational domain...

This article presents a data-based methodology to build Reynolds-Averaged Navier–Stokes (RANS) wall models for aerodynamic simulations at low Mach numbers. Like classical approaches, the model is based on nondimensional local quantities derived from friction velocity uτ, viscosity μw, and density ρw. A fully-connected neural network approximates relation u+=f(y+,p+). We consider reference data ...

In this study, a 3D combustion chamber was simulated using FLUENT 6.32. Aim to obtain detailed information on combustion characteristics and _ nitrogen oxides in the furnace and the effect of oxygen enrichment in a combustion process. Oxygenenriched combustion is an effective way to reduce emissions. This paper analyzes NO emission, including thermal NO and prompt NO. Flow rate ratio of air to ...

We numerically investigate stalling flow around a static airfoil at high Reynolds numbers using the Reynolds-averaged Navier–Stokes equations (RANS) closed with Spalart–Allmaras turbulence model. An arclength continuation method allows to identify three branches of steady solutions, which form characteristic inverted S-shaped curve as angle attack is varied. Global stability analyses these solu...

Turbine inlet temperatures in advanced gas turbines could be as high 2000 °C. To prevent ingress of this hot into the wheelspace between stator and rotor disks, whose metals can only handle up to 850 °C, rim seals sealing flows are used. This study examines abilities large eddy simulation (LES) based on WALE subgrid model Reynolds-averaged Navier–Stokes (RANS) SST predicting a rotor–stator conf...