Reynolds-averaged Navier-Stokes (RANS) is one of the most cost-efficient approaches to simulate wind-farm-atmosphere interactions. However, applicability RANS-based methods always limited by accuracy turbulence closure models, which introduce various uncertainties into models. In this study, we estimate model-form in RANS simulations wind farms. For purpose, compare different models a large-edd...

Three different cyclist positions were evaluated with Computational Fluid Dynamics (CFD) and wind-tunnel experiments were used to provide reliable data to evaluate the accuracy of the CFD simulations. Specific features of this study are: (1) both steady Reynolds-averaged Navier-Stokes (RANS) and unsteady flow modelling, with more advanced turbulence modelling techniques (Large-Eddy Simulation -...

The present work addresses the coupling of a flamelet database that can accurately represent the flame structure in composition space with a low-Mach approximation of the Navier-Stokes equations. An advancement of the CFI combustion model, which is currently based on laminar premixed flamelets, is used for chemistry tabulation. This model can be applied to different combustion regimes from prem...

The flow in and around a pair of plumes from sources that are vertically horizontally offset is investigated. An analytical potential model developed using an adapted version the Milne–Thomson circle theorem to represent due adjacent circular point sinks. This approximates horizontal section through plumes, which have differing radii at same vertical position. predictions this compared against ...

ven with great advances in computational techniques and computing power during recent decades, the modeling of unsteady separated flows, such as those encountered in the wake of a re-entry vehicle, continues to be one of the most challenging problems in CFD. Of most interest to the aerothermodynamics community is accurately predicting transient heating loads on the base of a blunt body, which w...

Predictions of the flow over a wall-mounted hump are obtained using solutions of the Reynolds-averaged Navier-Stokes (RANS) equations and Detached-Eddy Simulation (DES). The upstream solution is characterized by a two-dimensional turbulent boundary layer with a thickness approximately half of the maximum hump thickness measured at a location about two chord lengths upstream of the leading edge....

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...

Investigations of attached partial cavitation are important because to prevent damages in hydrulic machinery and to reduce the costs. As expected computational fluid dynamics (CFD) methods have been developed for more than 40 years to understand this phenomenon and to improve the machinery designs, as pumps and hydraulic turbines. However, cavitation appears at high Reynolds numbers, so that, t...

in this paper, the turbulent air droplet flow inside a single passage of a curved type vane separator has been studied numerically. the simulation is based on the eulerian - lagrangian method. for turbulent air flow calculations, a computer code was developed to solve the reynolds averaged navier stokes (rans) equations together with the equations of reynolds stress transport model (rstm) on co...

Both RaNS (Reynolds-averaged Navier-Stokes) and DES (Detached Eddy Simulation) type turbulence models were used in conjunction with a two-fluid model of bubbly flow and a new subgrid air entrainment model to predict air entrainment and transport in a hydraulic jump. It was found that the void fraction profiles predicted by both methods are in agreement with the experimental data in the lower sh...