Browsing by Subject "Turbulència -- Models matemàtics"
Now showing items 1-20 of 38
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A numerical strategy to compute optical parameters in turbulent flow: application to telescopes
(2008-07-29)
Article
Open AccessWe present a numerical formulation to compute optical parameters in a turbulent air flow. The basic numerical formulation is a large eddy simulation (LES) of the incompressible Navier-Stokes equations, which are approximated ... -
A refined statistical cloud closure using double-Gaussian probability density functions
(2013-10-08)
Article
Open AccessWe introduce a probability density function (PDF)-based scheme to parameterize cloud fraction, average liquid water and liquid water flux in large-scale models, that is developed from and tested against large-eddy simulations ... -
A study of the flow-field evolution and mixing in a planar turbulent jet using direct numerical simulation
(2002-01-10)
Article
Open AccessTurbulent plane jets are prototypical free shear flows of practical interest in propulsion, combustion and environmental flows. While considerable experimental research has been performed on planar jets, very few ... -
Advanced study for the numerical resolution of the Navier-Stokes equations. Application to turbulent flows in air curtains
(Universitat Politècnica de Catalunya, 2023-07-11)
Master thesis
Open AccessEl present treball exposa un estudi avançat de la resolució numèrica de les equacions multidimensionals de Navier-Stokes mitjançant mètodes computacionals. El projecte ha constat d’un detallat anàlisi teòric, a partir del ... -
Building proper invariants for large eddy simulation
(Springer, 2015)
Conference report
Restricted access - publisher's policy -
Calibration of Large Eddy Simulation parameters using Approximate Bayesian Computation
(Universitat Politècnica de Catalunya, 2022-10-20)
Master thesis
Open Access
Covenantee: University of Colorado BoulderApproximate Bayesian Computation (ABC) method is used to estimate posterior distributions of model parameters in subgrid-scale (SGS) closures for large eddy simulations (LES) of turbulent flows. The ABC approach avoids the ... -
Characterization of localized solutions of plane Poiseuille flow in very long domains
(Universitat Politècnica de Catalunya, 2016-05-24)
Bachelor thesis
Open AccessThe aim of this Bachelor's Thesis is the study of a particular low-energy localized plane Poiseuille solution while minimizing the error introduced by the streamwise periodicity boundary condition. The fact that the ... -
Coherent structures in a flow past a circular cylinder at critical and super-critical Reynolds numbers
(Springer, 2015)
Conference report
Restricted access - publisher's policyIt is well known that the wake topology in the flow past a circular cylinder remains almost unchanged up to Reynolds number ~105 Williamson (Annu Rev Fluid Mech 28(1), 477–539 (1996)) [1]. Then, at Re~2×105 major changes ... -
Coupling strategies for solving the RANS equations
(Universitat Politècnica de Catalunya, 2020-02-14)
Master thesis
Open Access
Covenantee: Deutsches Zentrum für Luft-und RaumfahrtFor the present work two implicit methods of coupling the compressible Reynolds Averaged Navier-Stokes equations in conjunction with the one equation Spalart-Allmaras turbulence model have been developed. The first approach, ... -
Detached-eddy simulation of a wall-mounted cylinder flow
(Universitat Politècnica de Catalunya, 2016-09-14)
Bachelor thesis
Open Access
Covenantee: Technische Universität MünchenThe aim of this project is to study the effect of different turbulence models on the detachment point on the cylinder surface and the vortex shedding frequencies. The turbulence models considered are Spallart-Allmaras DDES, ... -
Determination of the correlation between turbulence intensity and acoustic noise level-two clockwise-turning rotors case
(Universitat Politècnica de Catalunya / Lodz University of Technology, 2011)
Master thesis (pre-Bologna period)
Open AccessThe aim of this project is to find the correlation between turbulence intensity and acoustic noise level. To achieve this aim a test was performed on the 5th of April 2012 in the acoustic laboratory of the Technical ... -
DNS and LES for simulating stratocumulus: Better together
(2018-07-05)
Article
Open AccessWe argue that combining direct numerical simulation (DNS) with large-eddy simulation (LES) and field studies could accelerate current lines of stratocumulus research. LES allows for a faster and more holistic study of ... -
Estabilización en ciclos de turbulencia
(Universitat Politècnica de Catalunya, 2021-02-15)
Bachelor thesis
Restricted access - author's decisionTurbulence is one of the big reasons why passengers are afraid of flying. Taking into account that in a near future they will increase due to climate change and the large traffic of airplanes, it has been wanted to modify ... -
Estudi CFD del flux turbulent al voltant d'àleps de turbomàquines amb model SAS
(Universitat Politècnica de Catalunya, 2015-06-09)
Bachelor thesis
Open AccessEls models matemàtics descriuen amb la màxima precisió possible un sistema per mitjà del llenguatge matemàtic. Els models de turbulència són aquells que volen llegir i predir el comportament d’un fluid, normalment turbulent. ... -
Estudi de la resolució computacional de les equacions de Navier-Stokes aplicades a fluxos laminars i introducció a la turbulència
(Universitat Politècnica de Catalunya, 2021-06-22)
Bachelor thesis
Open AccessS'estudia la resolució, mitjançant mètodes numèrics i amb l'ajut del mètode dels volums finits, de les equacions de Navier Stokes. Es realitza una deducció matemàtica i es proposen un seguit de casos per a implementar la ... -
Experimental and numerical modeling of a sloshing problem in a stepped based rectangular tank
(2021-03)
Article
Open AccessIn this study, the two-dimensional sloshing of water in a stepped based tank partially filled was analyzed using an arbitrary Lagrangian–Eulerian adaptive fixed-mesh method and including the Smagorinsky turbulence model. ... -
Implications of non-local transport and conditionally averaged statistics on Monin- Obukhov similarity theory and Townsend ´s attached eddy hypothesis
(2018-10-01)
Article
Open AccessAccording to Townsend’s hypothesis, so-called wall-attached eddies are the main contributors to turbulent transport in the atmospheric surface layer (ASL). This is also one of the main assumptions of Monin–Obukhov ... -
Influencia del modelo de turbulencia y del refinamiento de la discretización espacial en la exactitud de las simulaciones computacionales de incendios
(Universitat Politècnica de Catalunya, 2008)
Article
Open AccessEl tratamiento de la turbulencia es un problema complejo al que se han dedicado innumerables investigaciones debido a que afecta sensiblemente a la exactitud de los resultados, determinando el comportamiento del flujo de ... -
Investigation of a novel numerical scheme for high-pressure supercritical fluids turbulence
(2022)
Research report
Open AccessHigh-pressure supercritical turbulence simulations are strongly susceptible to numerical instabilities. The multi-scale nature of the flow, in conjunction with the nonlinear thermodynamics and the strong density gradients ... -
Large eddy simulation of a turbulent diffusion flame: some aspects of subgrid modelling consistency
(2017-04-26)
Article
Open AccessIn the context of Large Eddy Simulation (LES) solely for the momentum transport equation there may be found several models for the turbulent subgrid fluxes. Furthermore, among those relying on the eddy diffusivity approach, ...
