Unsteady Flows
Mostrando 1-12 de 12 artigos, teses e dissertações.
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1. Numerical Simulation of a Pitching Airfoil Under Dynamic Stall of Low Reynolds Number Flow
ABSTRACT: In this research, viscous, unsteady and turbulent fluid flow is simulated numerically around a pitching NACA0012 airfoil in the dynamic stall area. The Navier-Stokes equations are discretized based on the finite volume method and are solved by the PIMPLE algorithm in the open source software, namely OpenFOAM. The SST k - ω model is used as the tur
J. Aerosp. Technol. Manag.. Publicado em: 14/11/2019
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2. Simulation of species concentration distribution in reactive flows with unsteady boundary conditions
Abstract The determination of species concentration profiles in reactive flows with variable inlets is a problem of practical interest to many fields such as in flow reactor transient operation and in cyclic degradable pollutants disposals in watercourses. In these cases, the inflow condition often consists of a time-dependent function, which may imply unste
Braz. J. Chem. Eng.. Publicado em: 2017-10
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3. Further Development and Application of High-Order Spectral Volume Methods for Compressible Flows
Abstract: The present paper investigates the high-order spectral finite volume method with emphasis on applicability aspects for compressible flows. The intent is to improve the understanding and implementation of numerical techniques related to high-order unstructured grid schemes. In that regard, a hierarchical moment limiter and high-order mesh capability
J. Aerosp. Technol. Manag.. Publicado em: 20/07/2017
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4. Aerodynamics of Harmonically Oscillating Aerofoil at Low Reynolds Number
ABSTRACT: Two-dimensional flows over harmonically oscillating symmetrical aerofoil at reduced frequency of 0.1 were investigated for a Reynolds number of 135,000, with focus on the unsteady aerodynamic forces, pressure and vortex dynamics at post-stall angles of attack. Numerical simulations using ANSYS® FLUENT CFD solver, validated by wind tunnel experimen
J. Aerosp. Technol. Manag.. Publicado em: 2017-03
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5. Feasible domain of Walker's unsteady wall-layer model for the velocity profile in turbulent flows
O presente trabalho estuda em detalhe o modelo parietal transiente de Walker et al. (1989, AIAA J., 27, 140-149) para perfis de velocidade em escoamentos turbulentos. Dois novos termos são adicionados ao sistema transcedental não linear de equações que é utilizado para determinar os três principais parâmetros do modelo. Os domínios matemático e fís
An. Acad. Bras. Ciênc.. Publicado em: 2014-12
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6. Density currents at steady regime
This work brings as its main contribution the study of the phenomenon of density currents in non-stratified reservoirs, with flows in steady regimes. Flows are analyzed for a wide range of Reynolds and Richardson numbers in the entrance of the reservoir. Based on this hypothesis, a hybrid numeric model is presented considering the Reynolds Transport's Equati
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2010-09
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7. Unsteady aerodynamic coefficients obtained by a compressible vortex lattice method.
Unsteady solutions for the aerodynamic coefficients of a thin airfoil in compressible subsonic or supersonic flows are studied. The lift, the pitch moment, and pressure coefficients are obtained numerically for the following motions: the indicial response (unit step function) of the airfoil, i.e., a sudden change in the angle of attack; a thin airfoil penetr
Publicado em: 2009
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8. A numerical model for thin airfoils in unsteady compressible arbitrary motion
A numerical method based on the vortex methodology is presented in order to obtain unsteady solution of the aerodynamic coefficients of a thin airfoil in either compressible subsonic or supersonic flows. The numerical model is created through the profile discretization in uniform segments and the compressible flow vortex singularity is used. The results of t
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2007-09
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9. Unsteady aerodynamic forces for aeroelastic analysis of two-dimensional lifting surfaces
The present work is part of an effort for developing a methodology for the aeroelastic analysis of two-dimensional lifting surfaces using an unsteady, Euler-based, CFD tool for the calculation of the aerodynamic operator. The CFD tool solves the flow problem with the finite-volume method applied to an unstructured grid context. The proposed methodology is ba
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2006-12
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10. On contribution of advanced vortex element methods toward virtual reality of unsteady vortical flows in the new generation of CFD
The purpose of this paper is to explain the attractive applicability of the advanced vortex element methods and their contribution to the beginning of the new generation of CFD, with introduction of epoch-making application of the methods to simulation of unsteady flows around bluff bodies and virtual operation of fluid machinery. The vortex methods have bee
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2004-12
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11. A study on correction methods for aeroelastic analysis in transonic flow.
The work presents a study of correction techniques to compute unsteady transonic pressure distributions and aeroelastic stability in this flow regime. The methodologies herein investigated are based on corrections of pressure distributions by the weighting of the lifting surface self-induced downwash, resulting from aeroelastic structural displacements or pr
Publicado em: 2004
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12. Computational model for the study unsteady open-channel flows / Modelo computacional para análise de transiente hidráulico em canais
This work presents a computational model developed in FORTRAN language for the study of unsteady open-channel flows with the use of Saint-Venant one-dimensional equation. The discretization of hydrodynamic equations are presented in a completely implicit method of finite differences and applied in the model for the investigation of two cases, besides the one
Publicado em: 2003