PNNL

Abstract

In order to increase hydropower capacity and maintain existing capacity, predictive simulation methods are needed that can reliably estimate the risk to fish passing through turbines, spillways, and other flow passage routes at hydropower facilities. To this end, one of the central challenges is to validate the software capabilities for simulating the trajectories, including collisions, of inertial particles against laboratory data. The following describes the design and results of such an experimental campaign. In this work, neutrally buoyant spherical and rod-shaped beads were released upstream of in laboratory scale geometries representative of the distributor of a hydro-turbine. The experimental campaign involved a test matrix of 24 configurations with variations in bead geometry, collision target geometry, flow speeds and release locations. A total of more than 10,000 beads were recorded using high-speed video cameras and analyzed using particle tracking software. The resulting data set provides a unique resource for the validation of computational approaches to fish passage through similar flow passage routes. Collision rates from 1%-7% were observed for the cylinder geometry and rates of 1%-23% were observed for the vane array over the range of test configurations. The increased dispersion of the beads with flow speed explained the decrease in collision rates for beads released with zero offset, and increased collision rates for those released at a lateral offset. The wicket gate angle had the effect of offsetting the mean of the lateral bead distribution, significantly decreasing the number of collisions observed in the lower 1% wicket gate angle relative to the upper 1% wicket gate angle.