Modeling and eddy simulation of rotating and curved turbulent flows
Is Version Of
In the first part of this work, two different approaches to incorporate the effects of rotation and curvature in scalar eddy viscosity models have been explored. One is the "Modified coefficients approach" - to parameterize the model coefficients such that the growth rate of turbulent kinetic energy is suppressed or enhanced. The other is the "Bifurcation approach" - to parameterize eddy-viscosity coefficient such that the equilibrium solution bifurcates from healthy to decaying solution branches. Simple, yet, predictive models in each of these two approaches are proposed and validated on some benchmark test cases characterized by profound effects of system rotation and/or streamline curvature. The results obtained with both the models are encouraging. Application of the models to some practically relevant flow configurations is also discussed.
In the second part, a computational framework is developed with recycling and rescaling method of inflow generation to perform eddy simulation of turbomachinery flows. A systematic validation is carried out on a spatially developing boundary layer on flat plate, flow through a channel and an annulus. Then, large eddy simulation of turbine transition duct is performed to demonstrate the effectiveness of this methodology.