Experimental Observation of Inertial Particles through Idealized Hydroturbine Distributor Geometry

To increase and maintain existing hydropower capacity within biological performance-based regulations, predictive simulation methods are needed that can reliably estimate the risk to fish passing through flow passage routes at hydropower facilities. One of the central challenges is to validate the software capabilities for simulating the trajectories, including collisions, of inertial particles against laboratory data. In this work, neutrally buoyant spherical- and rod-shaped beads were released upstream of laboratory-scale geometries representative of the distributor of a hydroturbine. 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. 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.

Application of Collision Detection in Visual Simulation System for Bridge Cranes

Collision detection is the key technology in the visual simulation system for bridge cranes. According to analyse the collision between hook and virtual objects in visual simulation system for bridge cranes, collision detection method of visual simulation system for bridge cranes is determined based on the collision detection principle. First of all, LOS intersection vector method is chosen based on the principle of collision detection in Vega. Hook is designed for the collision target using Isector module in Lynx and the same intersection vector masks in Isector Class are guaranteed. Then, the BUMP collision detection for hook is created by calling vgIsector functions in VC++ and BUMP detection method of hook is bounded with hook. Finally, conditional statements which ensure hook to move without collision are compiled. Therefore, the virtual scene around the hook is detected in real time. The results show that the phenomenon of passing through by mistake for the hook can be avoided applying the BUMP collision detection method in Vega software in visual simulation system for bridge cranes, and the accuracy for BUMP method detecting the goods is improved using LOS collision detection method.