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Showing 1 to 20 of 33 for “"RANS simulations"”.
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Effects of Turbulence Modeling on RANS Simulations of Tip Vortices
… of this thesis is to quantify the effects of RANS turbulence modeling on the resolution of free shear vortical flows. The simulation of aerodynamic wing-tip vortices is used as a test bed. The primary configuration is flow over an isolated finite wing with aspect ratio, , and Reynolds number, …
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Comparing Turbulent Dispersion Models for RANS Simulations of Particle-Laden Flows
… the field. Due to their low computational cost, RANS simulations remain the preferred method in the design phase of engineering solutions. The reduction in computational cost stems from the fact that RANS simulations neglect velocity fluctuations and solve for the time averaged velocity field. …
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Physics-Informed, Data-Driven Framework for Model-Form Uncertainty Estimation and Reduction in RANS Simulations
… resources has enabled high-fidelity simulations (e.g. large eddy simulation and direct numerical simulation) of turbulent flows, the Reynolds-Averaged Navier-Stokes (RANS) equations based models are still the dominant tools for industrial applications. However, the predictive …
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Predictive Turbulence Modeling with Bayesian Inference and Physics-Informed Machine Learning
Reynolds-Averaged Navier-Stokes (RANS) simulations are widely used for engineering design and analysis involving turbulent flows. In RANS simulations, the Reynolds stress needs closure models and the existing models have large model-form uncertainties. Therefore, the RANS simulations are known to …
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An improved panel method for the prediction of performance of ducted propellers
… type scheme). At the same time, full-blown RANS simulations of the three dimensional problem are conducted. The forces, i.e. thrust and torque on the propeller predicted by the present panel method under the improved wake alignment model show good agreement both with experimental …
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Improving turbomachinery loss prediction using high fidelity CFD
High fidelity simulations of three compressor cascades and a fundamental trailing edge flow are used to interrogate, and improve upon, the errors present in conventional RANS simulations. Using the optimum turbulence viscosity, calculated from the high fidelity simulations, it is found that error …
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Transport of Heat and Momentum In Non-Equilibrium Wall-Bounded Flows
<p>Transport of momentum and heat in non-equilibrium wall-bounded flows is studied analytically and experimentally to better understand the underlying physics, transition dynamics, and appropriate flow scaling in non-equilibrium flows. Non-equilibrium flows, in which the mean flow time scales are …
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A Computational Analysis of the Aerodynamics and Aeroacoustics of Jets with Fluid Injection
… so that performance is not affected. Numerical simulations are performed on a military-style nozzle based on the GE F400-series engines, with a design Mach number of 1:65, for over-expanded jet conditions. The effectiveness of the fluidic injection as noise reduction technique is analyzed for …
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A high-order, adaptive, discontinuous Galerkin finite element method for the Reynolds-Averaged Navier-Stokes equations
… of the Reynolds-Averaged Navier-Stokes (RANS) equations and an output-based error estimation and mesh adaptation algorithm for these discretizations. In particular, DG discretizations of the RANS equations with the Spalart-Allmaras (SA) turbulence model are examined. The dual consistency …
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Dynamics and stability of flow past a circular cylinder in ground effect
… It is subsequently shown that detached-eddy simulations (DES) can correctly reproduce these critical phenomena, whereas unsteady RANS simulations predict them at much smaller h/d of between 0.1 and 0.2, despite the fact that the unsteady RANS simulations are 'overly dissipative' compared with …
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Unsteady flamelet progress variable modeling of reacting diesel jets
… The models should be able to predict the transient physical and chemical processes in the jets such as ignition and flame lift-off. In the first part of this work, an existing unsteady flamelet progress variable (UFPV) model is employed in Reynolds-averaged Navier-Stokes (RANS) simulations …
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Experiments and simulation of shaped film cooling holes fed by crossflow with rib turbulators
… fed by a smooth internal channel, as well as RANS simulations performed for select cases. The film cooling hole discharge coefficients and channel friction factors were measured for both rib configurations. Spatially-averaged film cooling effectiveness behaves similarly to holes fed by a …
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Comparative Evaluation of Vorticity Transport Modeled Distortions and High-Fidelity ANSYS Solutions Using Modal Assurance Criterion
… work presents the evaluation of a vorticity transport based reduced order model (ROM) in comparison to similar data created through Ansys CFX simulation for three canonical swirl flow profiles: Bulk Swirl, Twin Swirl, and Quad Swirl. Modal decomposition through singular value decomposition …
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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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Neural Operators for Learning Complex Nonlocal Mappings in Fluid Dynamics
… a focus on Reynolds-Averaged Navier--Stokes (RANS) models, which will continue to serve as the backbone for many practical aircraft applications. Specifically, in RANS turbulence modeling, the challenges include developing more efficient ensemble filters to learn nonlinear eddy viscosity …
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A methodology for centrifugal compressor stability prediction
… force fields based on steady, single-passage 3-D RANS simulations and a look-up table approach to capture the dependence of the body forces on the local flow parameters. The body force model was implemented in a finite volume scheme of an existing unsteady Euler solver for a full-wheel domain …
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Investigation into the optimal cooling configuration for a gas turbine airfoil utilizing a thermal barrier coating
… configurations for an airfoil. In this study RANS computational simulations were used to determine the optimal cooling configuration for a flat plate with a single row of film cooling holes and TBC. A variety of parameters were iterated upon to determine a film cooling configuration that …
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Estudio integral del flujo en la turbina y la estela de aerogeneradores experimentales
… como términos fuente en las ecuaciones RANS no estacionarias con modelo de turbulencia k-e. El aerogenerador MEXICO se representó con un modelo directo. Como primera aproximación, se hizo un estudio sistemático con simulaciones estacionarias y no estacionaras de las ecuaciones RANS con …
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Investigation of S-shaped intake aerodynamics using computational fluid dynamics
… engine face. Reynolds Averaged Navier-Stokes (RANS) simulations have been considered using the SA, k- ω and SST turbulence models where possible. The freestream Mach number was fixed at 0.21 and the Reynolds number based on the non-dimensional engine face diameter was 777,000 for all cases. The …
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An adaptive variational multiscale method with discontinuous subscales for aerodynamic flows
… Adaptive DG and VMSD are compared for 3D RANS simulations. The adaptive VMSD method is shown to produces solutions with the same drag error as the adaptive DG method, with a factor of 3-10 fewer globally coupled degrees of freedom, and an associated factor of three or more reduction in …
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