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Showing 1 to 20 of 57 for “"two-equation"”.
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Extension to Multiple Species of a Two-Equation Turbulence Model for High Speed Flows
<p>The Wilcox (2006) <em>k-co </em>turbulence model has been extended to multiple species and implemented in a CFD code for high speed flows using the Steger-Warming flux-vector splitting scheme. The model was chosen because compressibility corrections are not required, nor are viscous damping …
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Analysis of the wake behind a propeller using the finite element method with a two-equation turbulence model
… set of the Reynolds time-averaged Navier-Stokes equations and two turbulence transport equations for the turbulent kinetic energy and its rate of dissipation was solved by L/U decomposition and successive substitution with relaxation. An existing finite element code was modified with a low …
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A numerical simulation of two-dimensional separated flow in a symmetric open-channel expansion using the depth-integrated two-equation (K-E) turbulence closure model
… analyzed by means of the depth-integrated equations of motion. A consequence of adopting a depth-integrated modeling approach is that closure approximations must be implemented to represent the so-called effective stresses. The effective stresses consist of the depth-integrated viscous …
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Evacuation Distributed Feedback Control and Abstraction
… by nonlinear hyperbolic partial differential equations. As such the system is distributed in nature. We address the design of feedback control for these models in a distributed setting where the problem of control and stability is formulated directly in the framework of partial differential …
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Chebyshev spectral method for incompressible viscous flow with boundary layer control via suction or blowing
… quasi 3-D design/analysis code implements a two-equation integral method with empirical closure relations to solve the boundary layer flow problem with or without suction, but lacks the option of flow control via blowing. The integral method is parameterized with the shape parameter H _ 6*/0 …
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Turbulence modeling for film cooling flows
An improved two equation turbulence model has been developed in this dissertation to better predict the complex film cooling flow field that is formed from the interaction of a coolant jet and a crossflow over a modeled turbine blade surface. Film cooling of turbine blades is commonly employed to …
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Bayesian and nonBayesian Techniques for Forecasting Monthly Cattle Prices
… turning point criteria. The economic model is a two-equation recursive system of supply and demand whose reduced form is used as the forecasting equation for the econometric model and is also the information set on which all other models are based. The econometric analysis is based on constant, …
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CFD Performance of Turbulence Models for Flow from Supersonic Nozzle Exhausts
… to assess the performance of various one- and two-equation turbulence models for accurately predicting the supersonic plume flow. One particular turbulence model of interest is the Wray-Agarwal (WA) turbulence model. This is a neat model which has demonstrated promising results mimicking the …
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A numerical investigation of self-sustained cavity flow oscillations
Two-dimensional (2-D) cavity flow physics and oscillation control were investigated through solutions of the Reynolds-Averaged Navier-Stokes equations coupled with a two-equation k-? turbulence model. Effects of the leading edge modifications including compression ramps, expansion surfaces and mass …
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Modelling of turbulent swirling flows
… and reacting combustion chambers. The transport equations for title k -e and k - w two-equation turbulence models are presented along with the LRR and SSG second-moment closure models for isothermal and variable density flows. The effect of anisotropy in the Reynolds stress dissipation rate …
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A numerical investigation of compressible flow in a curved S-duct
… of the Reynolds-averaged Navier-Stokes equations on an unstructured grid in three spatial dimensions. Results are compared to existing experimental steady-state data to validate the computed solutions. Effects of grid resolution, including boundary layer spacing and localized refinement …
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Development of a One-Equation Eddy Viscosity Turbulence Model for Application to Complex Turbulent Flows
… flows using the Reynolds-Averaged Navier-Stokes equations in conjunction with a turbulence model. The goal of this research has been to develop an eddy viscosity type turbulence model to increase the accuracy of flow simulations for mildly separated flows, flows with rotation and curvature …
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Numerical modeling and simulation of compressible reacting turbulent shear layers
… data. The new compressible models are one-equation and two-equation algebraic Reynolds stress models (ASMs), which account for variations in the anisotropy of the normal stresses through modification of the pressure-strain terms of the Reynolds stress transport equations. In contrast to …
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Horizontal Shear Transfer for Full-Depth Precast Concrete Bridge Deck Panels
… further investigation. Currently, all design equations, both in the AASHTO Specifications and the ACI code, are based upon research for cast-in-place slabs. The introduction of a grouted interface between the slab and beam can result in different shear resistances than those predicted by …
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Numerical Investigation of Mixing Tabs in Multi-Ring Entraining Diffuser in Air-Air Ejectors
… of tab performance were carried out using two-equation κ-ɛ turbulence models with enhanced wall treatment available in ANSYS Fluent on an ejector obtained from a prior thesis [1]. Only triangular tabs were considered on the ejector. Tab number was varied with 4, 8 and 12 tabs. Increasing …
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Theory of Detonation Structure for Two-Phase Materials
The structure of a two-phase steady detonation in a granulated solid propellant has been studied, and existence conditions for a one-dimensional, steady two-phase detonation have been predicted. Ordinary differential equations from continuum mixture theory have been solved numerically to determine …
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Application of hybrid Computational Fluid Dynamics turbulence model, STRUCT-[epsilon], on heated flow cases
… which are traditionally over-predicted with two-equation models. Most notably, STRUCT-[epsilon]s method of implicit hybrid activation is uniquely simple to implement while remaining grid-size and inlet turbulence condition independent. STRUCT-[epsilon], has previously demonstrated improved …
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Computational study of hub corner stall in an axial compressor rotor
… solver, the Moore Elliptic Flow Program. A one equation, q-L, transitional turbulence model was used with MEFP for closure of the transport equations. The calculation was used to study the physics and flow mechanisms affecting hub corner stall. Preprocessing and post processing programs were …
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Estimating the demand for money in a developing country
… Distributed Lag (ARDL) model using a two equation technique that includes cointegration and an error-correction model (ECM). The cointegration model estimates the long-run relation that might exists between the dependent variable and the explanatory variables, and the ECM determines …
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The computer modelling and experimental study of confined jet mixing with application to jet pump design
… been undertaken. A so-called Prandtl-Kolmogorov two-equation turbulence model, with turbulent kinetic energy k and turbulent energy dissipation rate E as the two parameters, is incorporated into the time-mean Navier-Stokes equations to form a complete set of partial differential equations which …
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