Optimization of Kaplan Hydro-Turbine at Very Low Head With Rim-Driven Generator

The objective of the paper is to study the design and optimization of Kaplan hydro turbines for very low head (less than 3 meters), with a particular emphasis on the use of rim-drive electrical generators. The work is based on Computation Fluid Dynamics (CFD) analysis of a variety of design parameters for maximum output power and efficiency. Two designs are presented in the paper. One is a 90-cm (35-inch) diameter vertical-oriented Kaplan hydro turbine systems as an intended product capable of generating over 50 kW. The other is a smaller, 7.6-cm (3-inch) diameter horizontal-oriented system for prototyping and laboratory verification. Both are analyzed through CFD based on Large Eddy Simulation (LES) of transient turbulence. Certain design for the runner and the stator as well as guide vanes upstream of the turbine were studied to get the most from the available head. The intent is to use 3D-printing manufacturing techniques, which may offer original design opportunities as well as the possibility of turbine and water conduit design customization as a function of the head and flow available from a specific site.