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Showing 1 to 12 of 12 for “"Hybrid RANS/LES"”.
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Computational aeroacoustic modelling using hybrid RANS/LES methods with modified acoustic analogies
… as well as the corresponding propagations. A hybrid IDDES turbulence model is employed, to compute the boundary layer and fluctuations in the flow properties. Larsson et al. modified Curle's analogy leading to the derivation of a version of Curle's analogy that makes use of strictly time …
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Wall-models for large eddy simulation based on a generic additive-filter formulation
… approaches are addressed by deriving the exact hybrid RANS/LES Navier-Stokes equations. These equations are derived by introducing an additive-filter, which linearly combines the RANS and LES operators with a blending function. The equations derived predict additional hybrid terms, which …
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Turbulence Modelling for Complex Flows in Turbomachinery
… the underlying physics of this complex flow, the RANS turbulence closure models and a hybrid RANS-LES method are developed and extended. The improved RANS and hybrid RANS-LES models are shown to be able to predict the corner separation flows with significantly improved accuracy, and are expected …
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Numerical Modelling of Shock Wave Boundary Layer Interactions in Aero-engine Intakes at Incidence
… (SWBLIs). Reynolds-Averaged Navier Stokes (RANS) turbulence models have been shown to be insensitive to the effects of boundary layer relaminarisation present in these highly-accelerated flows. Further, downstream of the SWBLI, RANS methods fail to capture the distorted flow that propagates …
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A qualitative assessment and optimization of URANS modelling for unsteady cavitating flows
… is characterized by the formation of vapor bubbles when the pressure in a working fluid drops sharply below the vapor pressure. These bubbles, upon exiting the low-pressure region burst emanating tremendous amounts of energy. Unsteady cavitating flows have been influential in several aspects …
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A Preliminary Study of Acoustic Prediction Technology Based on Detached Eddy Simulations for Supersonic Jets Impinging on Flat Plates
… exit. All turbulence modeling is done using a hybrid RANS/LES technique known as Delayed Detached Eddy Simulation (DDES). A transient solution is calculated using the pressure-based coupled solver formulation with the second-order bounded central-upwind spatial discretization and second-order …
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Eddy-resolving simulations of the flow around a vertical tail plane
… uses steady Reynolds-Averaged Navier-Stokes (RANS) simulations to analyse VTPs flow. In order to assess RANS performance, the study of airflow detaching from a backward rounded ramp is performed and the results are compared to Large-Eddy Simulations (LES). The analysis shows that, even though …
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Thermoacoustic Effects of a Variable Equivalence Ratio in a Single Element Methane Combustor
… in Fluent with finite rate chemistry and a hybrid RANS/LES approach. The acoustic analysis and power spectral densities were done with a Fast Fourier Transform algorithm.</p> <p>The dominant frequencies, found to be between 1463 Hz and 1551 Hz, compare well with the experimental result of …
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A Stress-equivalent Spalart-Allmaras Wall Model with Local Boundary Conditions for RANS, DES, and LES
… the Spalart-Allmaras (SA) turbulence model that lessens the near-wall grid requirements. This is achieved by, below the log layer, making the eddy viscosity approach a constant, non-zero value, and the velocity, which has a non-zero slip, varying approximately linearly with distance from the wall …
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Turbulence Modeling and Simulation of Unsteady Transitional Boundary Layers and Wakes with Application to Wind Turbine Aerodynamics
… of unsteady high Reynolds number flows. A hybrid RANS/LES turbulence model integrated with transition formulation is developed and tested by a surrogate model problem through joint experimental and computational fluid dynamics approaches. The model problem consists of a circular cylinder …
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The Effects of Curvature on Turbulent Boundary Layers Over a 3D Bump Geometry: An Experimental Study Using BeVERLI Hill
… using the Benchmark Validation Experiment for RANS and LES Investigations (BEVERLI) Hill setup. The study focuses on analyzing the flow behavior over a three-dimensional bump geometry that incorporates both concave and convex surfaces, with the aim of improving the understanding of the complex …
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Simulations of droplet dispersion in the wakes of cylinders and icing tunnel spray bars
… the turbulent air flow was investigated with a hybrid Reynolds-Averaged Navier-Stokes/Large-Eddy Simulations approach scheme. In the first study, droplets were injected downstream of a cylinder at sub-critical conditions (i.e. with laminar boundary layer separation). A stochastic continuous …