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Showing 1 to 18 of 18 for “"Boussinesq approximation"”.
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Computational simulation of buoyancy-driven flows using vortex methods
… along with the vorticity transport equation and Boussinesq approximation to yield the baroclinically-generated vorticity field, also in a discrete form. The corresponding velocity field is then computed using a vorticity-streamfunction scheme similar to the vortex-in-cell approach. Complete …
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Distributed Parameter Control of Thermal Fluids
… flow by feedback. The system is governed by the Boussinesq approximation of the coupled set of Navier-Stokes and heat equations. The control is applied through Dirichlet boundary conditions. We concentrate on a two-dimensional mode and use a semidiscrete Galerkin scheme for numerical …
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The unstructured grid incompressible Navier-Stokes algorithm for convective heat transfer based on artificial compressibility
… in a strongly coupled manner is presented. The Boussinesq approximation is utilized to account for thermal buoyancy. The method of artificial compressibilty is used to solve the resulting equations in a time marching fashion. Roe's approximate Riemann solver is used for the construction of the …
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The evaluation of turbulence models using tensor visualization techniques
… formulations of the Reynolds stress tensor, the Boussinesq approximation and the Algebraic Reynolds Stress Model (ARSM), are studied. Glyphs based upon these two formulations and experimentally measured Reynolds stresses are compared in two flow geometries: fully developed pipe flow and a tip …
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Numerik für die Marangoni-Konvektion beim Floating-Zone Verfahren
… und der Wärmeleitungsgleichung in <br>Boussinesq-Approximation zu lösen. <br>Zunächst werden effiziente numerische Verfahren entwickelt zur Lösung der <br>Navier--Stokes Gleichungen mit Slip-Randbedingung und damit zur <br>Floating-Zone-Simulation bei vorgegebener …
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Assessment of RANS Turbulence Models for Hypersonic Flat Plates
… turbulent kinetic energy budget terms, and the Boussinesq approximation fails in capturing Reynolds normal stresses. For wall quantities, both models generally have increased errors at the lowest and highest Reynolds numbers studied, with the skin friction having increased errors with lower …
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Asymptotic analysis of mass-dominated convection in a nanofluid
… The suspension is heated from below. A quasi-Boussinesq approximation has been adopted i.e. the density will be assumed constant except in the gravity term where it depends on both temperature and concentration. But both the fluid viscosity and the coefficient of the particle diffusion are …
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Analysis of Numerical Methods for Incompressible Multiphase Flows with Thermal Convection
… equations and the temperature equation under the Boussinesq approximation. Unlike traditional schemes that rely on using the temperature and velocity as primary variables, our schemes use the momentum and internal energy. In addition, our schemes involve a semi-implicit projection method, which …
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Studying 3D Spherical Shell Convection using ASPECT
… convection cases. All cases use the Boussinesq approximation. The 2D cases come from Blankenbach et al. (1989), van Keken et al. (1997), and Davies et al. (in preparation). Results for 2D cases agree well with their respective benchmark papers. The time-evolutions of the root mean …
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Variational multiscale method for coupled systems: free-surface flows and stratified turbulence
… in thermodynamics for incompressible flow with Boussinesq approximation, an energy conservation equation is appended that gives rise to a thermomechanically coupled system. The coupled fine-scale sub-problem is locally resolved to yield the closure model. The fine-scale turbulence features are …
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Improving turbomachinery loss prediction using high fidelity CFD
… for this are found: errors arising from the Boussinesq approximation, and the fact that the correct time-averaged flow is an unstable solution of the RANS equations, leading to convergence issues. It is shown that, despite not being able to stabilise the RANS equations on the correct mean …
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Turbulent Simulations of a Buoyant Jet-in-Crossflow
… Navier--Stokes equations (NSE) under the Boussinesq approximation is utilized. Temperature and salinity scalar transport equations are utilized in conjunction with a linear equation of state (EOS) to obtain the density field and thus the buoyancy forcing. Comparing simulation data to …
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Computations of bubble dynamics with heat transfer
… transfer, buoyancy driven flow of air with the Boussinesq approximation has been studied. However, convective heat transfer in water cannot be modelled using the Boussinesq approximation, so a variable thermal property model has been included and validated against published experimental results. …
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A Numerical Study of Unsteady Natural Convective Heat Transfer From Thin, Two-Sided Heated Horizontal Plates of Various Shapes
… used to conduct the numerical simulations. The Boussinesq approximation was used, where the thermal properties of the air were kept constant, except for density, which decreased with an increase in temperature. Laminar and Standard k-epsilon turbulence models were used for computing the …
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Direct Assessment and Investigation of Nonlinear and Nonlocal Turbulent Constitutive Relations in Three-Dimensional Boundary Layer Flow
… constitutive relations, i.e., the standard Boussinesq approximation. The tested eddy viscosity models fail in the highly accelerated hill top region of the BeVERLI hill and near separation. In a further step, several nonlinear and nonlocal turbulent constitutive relations, including the QCR …
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Large Eddy Simulations of Flow and Heat Transfer in the Developing and 180° Bend Regions of Ribbed Gas Turbine Blade Internal Cooling Ducts with Rotation - Effect of Coriolis and Centrifugal Buoyancy Forces
… strong flow impingement on the back wall. The Boussinesq approximation is used in the buoyancy calculations, but the accuracy of the approximation comes into question in the presence of large temperature differences. A variable property algorithm is developed to calculate unsteady low speed …
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Implementation and Validation of the ζ-F and ASBM Turbulence Models
… models which add extra high-order terms to the Boussinesq approximation. According to Kassinos and Reynolds, however, this technique is fundamentally flawed. These models fail to capture all relevant information about the turbulence structure. The Reynolds stresses capture information regarding …
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Shear flow instabilities in stratified magnetohydrodynamics
… shear flow in different parameter regimes of the Boussinesq magnetohydrodynamic (MHD) framework, extending the two-dimensional (2D) model from Balmforth (2002) to include a uniform horizontal magnetic field aligned with the direction of flow streaming. Using linear stability analysis, we find that …