Combustor air flow prediction capability comparing several turbulence models

1989 ◽  
Vol 5 (2) ◽  
pp. 242-248 ◽  
Author(s):  
D. L. Rhode ◽  
S. T. Stowers
Keyword(s):  
Air Flow ◽  
Turbulence Models ◽  
Flow Prediction ◽  
Prediction Capability

scholarly journals Impact of Turbulence Models on the Air Flow in a Confined Rectangular Space

2020 ◽  
pp. 46-53
Author(s):  
Jakub Mularski ◽  
Amit Arora ◽  
Muhammad Azam Saeed ◽  
Łukasz Niedźwiecki ◽  
Samrand Saeidi
Keyword(s):  
Experimental Data ◽  
Air Flow ◽  
Turbulence Models ◽  
The Other ◽  
Experimental Measurements ◽  
Wall Region ◽  
Sst Model ◽  
Computational Fluid Dynamics Cfd ◽  
The Impact ◽  
The Given

The paper regards the impact of four different turbulence models on the air flow pattern in a confined rectangular space. The following approaches are analyzed. The Baseline (BSL) Reynolds model, the Speziale-Sarkar-Gatzki (SSG) Reynolds model, the Menter's shear-stress transport (SST) model and the basic k-ε model. Computational fluid dynamics (CFD) results are compared with the experimental measurements in four different planes. The Reynolds number for the given conditions is equal to 5000. The k-ε model yielded the most accurate results with regard to the experimental data but its reliability decreased near the wall region. With respect to the other models, it was also found that the k-ε approach generated the least circulating flow.

Numerical Simulation of Cavitating Flow Around a Hydrofoil

2014 ◽  
Author(s):  
Tan Dung Tran ◽  
Bernd Nennemann ◽  
Thi Cong Vu ◽  
François Guibault
Keyword(s):  
Turbulence Models ◽  
Cavitating Flow ◽  
Navier Stokes ◽  
Naval Academy ◽  
Cavitating Flows ◽  
Compressibility Effect ◽  
Hybrid Meshes ◽  
Fortran Code ◽  
Cavitation Tunnel ◽  
Prediction Capability

The objective of this paper is to evaluate the applicability of different cavitation models and determine appropriate numerical parameters for cavitating flows around a hydrofoil. The simulations are performed for a NACA 66 foil at 6 degrees angle of attack, Reynolds number of 750 000 and for a cavitation number of 1.49 corresponding to the partial sheet cavitating regime. The incompressible, multiphase Reynolds-averaged Navier-Stokes (RANS) equations are solved by the CFD solver CFX with Kubota and Merkle cavitation models. As part of the work, the Merkle model is implemented into CFX by User Fortran code because this model has shown good cavitation prediction capability according to the literature. The effects of the k-ε and SST turbulence models on the cavitating flow dynamics are compared. Also, an investigation on structured and hybrid meshes with different mesh sizes and concentrations is carried out in order to better understand the mesh influence for this cavitation simulation. The local compressibility effect is considered by correcting the turbulent eddy viscosity inside the mixture vapor/liquid zones. The numerical results are validated by experiments conducted in a cavitation tunnel at the French Naval Academy.

Experimental and Numerical Analysis of the air Flow in T-Shape Channel Flow / Eksperymentalna i numeryczna analiza przepływu powietrza przez skrzyżowanie kanałów w kształcie litery T

2013 ◽  
Vol 58 (2) ◽  
pp. 333-348 ◽  
Author(s):  
Janusz Szmyd ◽  
Marian Branny ◽  
Michal Karch ◽  
Waldemar Wodziak ◽  
Marek Jaszczur ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Air Flow ◽  
Turbulence Models ◽  
Reynolds Stress Model ◽  
Laboratory Model ◽  
Image Velocimetry ◽  
Stereo Particle Image Velocimetry ◽  
Rsm Model ◽  
Calculated Velocity ◽  
Real Flow

This paper presents the results of experimental and numerical investigations of air flow through the crossing of a mining longwall and ventilation gallery. The object investigated consists of airways (headings) arranged in a T-shape. Maintained for technological purposes, the cave is exposed particularly to dangerous accumulations of methane. The laboratory model is a certain simplification of a real longwall and ventilation gallery crossing. Simplifications refer to both the object’s geometry and the air flow conditions. The aim of the research is to evaluate the accuracy with which numerical simulations model the real flow. Stereo Particle Image Velocimetry (SPIV) was used to measure all velocity vector components. Three turbulence models were tested: standard k-ε, k-ε realizable and the Reynolds Stress Model (RSM). The experimental results have been compared against the results of numerical simulations. Good agreement is achieved between all three turbulence model predictions and measurements in the inflow and outflow of the channel. Large differences between the measured and calculated velocity field occur in the cavity zone. Two models, the standard k-ε and k-ε realizable over-predict the measure value of the streamwise components of velocity. This causes the ventilation intensity to be overestimated in this domain. The RSM model underestimates the measure value of streamwise components of velocity and therefore artificially decreases the intensity of ventilation in this zone. The RSM model provides better predictions than the standard k-ε and k-ε realizable in the cavity zone.

INVESTIGATION OF INLET EFFECTS ON BACKWARD-FACING STEP FLOW PREDICTION

2016 ◽  
Vol 40 (3) ◽  
pp. 317-329 ◽  
Author(s):  
Mustafa Kemal Isman
Keyword(s):  
Experimental Data ◽  
Turbulence Models ◽  
Navier Stokes ◽  
Backward Facing Step ◽  
Step Flow ◽  
Uniform Velocity ◽  
Flow Prediction ◽  
Rans Turbulence Models ◽  
Negative Effect ◽  
Inlet Boundary Condition

The turbulent flow over backward-facing step (BFS) is numerically investigated by using FLUENT® code. Both uniform and non-uniform velocity profiles are used as inlet boundary condition. Five different Reynolds averaged Navier–Stokes (RANS) turbulence models are employed. The Std. k–ω model shows the best agreement with the experimental data among the models used under the conditions considered in this study. The results show that using a uniform velocity profile has a negative effect on predictions if the domain is not sufficiently extended upstream from the inlet. To eliminate this effect, the domain should be extended upstream by about 10Dh from the inlet. However, results show that this extension causes absorption effects of inlet parameters such as inlet turbulence intensity.

scholarly journals PREDIÇÃO DE ESCOAMENTO DE AR EM UM SECADOR TIPO TÚNEL: AVALIAÇÃO DO USO DE PLACAS DE DIRECIONAMENTO DE FLUXO E DE MODELOS DE TURBULÊNCIA / PREDICTION OF AIR FLOW IN A TUNNEL TYPE DRYER: EVALUATION OF THE USE OF PLATES DIRECTION OF FLOW AND TURBULENCE MODELS

2020 ◽  
Vol 6 (10) ◽  
pp. 82819-82828
Author(s):  
Paula Giarolla Silveira ◽  
Jefferson Luiz Gomes Corrêa ◽  
Roney Alves da Rocha ◽  
Gustavo Pathelly Damasceno ◽  
Ronaldo Elias de Mello Júnior ◽  
...  
Keyword(s):  
Air Flow ◽  
Turbulence Models

scholarly journals TURBULENCE MODELS APPLIED TO CLASSICAL FLUID MECHANICS AND HEAT TRANSFER PROBLEMS - THE PERFORMANCE EVALUATION OF THE OPEN SOURCE CFD PACKAGE OPENFOAM

2021 ◽  
Vol 1 (5) ◽  
pp. e1539
Author(s):  
Paulo Rocha ◽  
Felipe Pinto Marinho ◽  
Victor Oliveira Santos ◽  
Stéphano Praxedes Mendonça ◽  
Maria Eugênia Vieira da Silva
Keyword(s):  
Heat Transfer ◽  
Fluid Mechanics ◽  
Open Source ◽  
Numerical Solutions ◽  
Turbulence Modeling ◽  
Air Flow ◽  
Turbulence Models ◽  
Parallel Plates ◽  
Averaged Equations ◽  
Rans Turbulence Models

Topics related to the modeling of turbulent flow feature significant relevance in several areas, especially in engineering, since the vast majority of flows present in the design of devices and systems are characterized to be turbulent. A vastly applied tool for the analysis of such flows is the use of numerical simulations based on turbulence models. Thus, this work aims to evaluate the performance of several turbulence models when applied to classic problems of fluid mechanics and heat transfer, already extensively validated by empirical procedures. The OpenFOAM open source software was used, being highly suitable for obtaining numerical solutions to problems of fluid mechanics involving complex geometries. The problems for the evaluation of turbulence models selected were: two-dimensional cavity, Pitz-Daily, air flow over an airfoil, air flow over the Ahmed blunt body and the problem of natural convection between parallel plates. The solution to such problems was achieved by utilizing several Reynolds Averaged  Equations (RANS) turbulence models, namely: k-ε, k-ω, Lam-Bremhorst k-ε, k-ω SST, Lien-Leschziner k-ε, Spalart-Allmaras, Launder-Sharma k-ε, renormalization group (RNG) k-ε. The results obtained were compared to those found in the literature which were empirically obtained, thus allowing the assessment of the strengths and weaknesses of the turbulence modeling applied in each problem.

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