NONLINEAR DYNAMICS ON CENTRE MANIFOLDS DESCRIBING TURBULENT FLOODS: k-ω MODEL
نویسندگان
چکیده
In shallow turbulent flows such as floods and tsunami vertical mixing tends to smooth out the flow characteristics in cross-sectional direction. The evolution of the average cross-flow characteristics presents considerable interest. We model such flows using the k-ω model of turbulence in the framework of the centre manifold theory. We tested the approach on an artificial diffusion problem for which an exact analytical solution is derived. Then we apply the method to model the turbulent flows and deduced the evolution equations for the average velocity, turbulent energy and its rate of dissipation.
منابع مشابه
Modelling the Dynamics of Turbulent Floods
Consider the dynamics of turbulent flow in rivers, estuaries and floods. Based on the widely used k-ǫ model for turbulence, we use the techniques of centre manifold theory to derive dynamical models for the evolution of the water depth and of vertically averaged flow velocity and turbulent parameters. This new model for the shallow water dynamics of turbulent flow: resolves the vertical structu...
متن کاملAssessment of Turbulent Models in Computation of Strongly Curved Open Channel Flows
Several rigorous turbulent models have been developed in the past years and it can be seen that more research is needed to reach a better understanding of their generality and precision by verifying their applications for distinct hydraulic phenomena; under certain assumptions. This survey evaluates the performance of Standard k-ε, Realizable k-ε, RNG k-ε, k-ω and RSM models in predicting flow ...
متن کاملEvaluation of the Centre Manifold Method for Limit Cycle Calculations of a Nonlinear Structural Wing
In this study the centre manifold is applied for reduction and limit cycle calculation of a highly nonlinear structural aeroelastic wing. The limit cycle is arisen from structural nonlinearity due to the large deflection of the wing. Results obtained by different orders of centre manifolds are compared with those obtained by time marching method (fourth-order Runge-Kutta method). These comparis...
متن کاملEffects of Different Turbulence Models in Simulation of Unsteady Tip Leakage Flow in Axial Compressor Rotor Blades Row
Characteristics of rotor blade tip clearance flow in axial compressors can significantly affect their performance and stable operation. It may also increase blade vibrations and cause detrimental noises. Therefore, this paper is contributed to investigate tip leakage flow in a low speed isolated axial compressor rotor blades row. Simulations are carried out on near-stall condition, which is val...
متن کاملTurbulent Flow in 2-D Domains with Complex Geometry-Finite Elelment Method
Using the highly recommended numerical techniques, a finite element computer code is developed to analyse the steady incompressible, laminar and turbulent flows in 2-D domains with complex geometry. The Petrov-Galerkin finite element formulation is adopted to avoid numerical oscillations. Turbulence is modeled using the two equation k-ω model. The discretized equations are written in the form o...
متن کامل