Parameter Identification of a Reduced-Order Model for the Reconfigurable Ducted Turbine Array Concept

This paper presents a reduced-order equivalent circuit model of the reconfigurable ducted turbine array concept. The fluid effects of a duct are categorized into: (1) ideal flow effects, (2) skin friction for laminar flow, and (3) boundary layer separation and vortex shedding for turbulent flow. Flow behavior as a function of duct aspect ratio and contraction ratio are investigated. Flow resistances in the equivalent circuit model are identified using computational fluid dynamics simulations. The objective of this research is to develop a control-oriented reduced-order equivalent circuit model for the proposed system for use in analysis and control co-design optimization. It is shown that a short duct geometry and a low contraction ratio has less flow resistance. The mass flow rate, which is shown to be proportional to the extractable hydrokinetic power, is enhanced at the throat region for contracted short ducts. Lastly, it is demonstrated that the mass of the duct is mainly proportional to aspect ratio.