Author(s): Joachim Lengricht; Kai-Uwe Graw; Henriette Katscher; Michael Peukert

Linked Author(s): Joachim Lengricht

Keywords: Baffle blocks; Supercritical flow; Hydraulic efficiency; Drag forces

Abstract: Different concepts have been introduced in hydraulic engineering to ensure energy dissipation in stilling basins, to fix the transition of supercritical into subcritical flow in a controllable area and to avoid objectionable downstream scour. The design of stilling basins is always in the focus when considering hydraulic jumps. One of the concepts is to positively affect - i. e. to increase - energy dissipation by internals such as baffle blocks, sills of various designs and associated devices. However, baffle blocks with a geometry variable in all three directions in space are almost unexplored. Primary objective of the presented investigations was to explore the hydraulics of pyramidal bodies in supercritical flow. As object of comparison the well-investigated cubical shape was chosen. Hydraulic efficiencies and characteristic flow fields around pyramidal and cubical shapes were studied. Drag forces on pyramidal and cubical baffle blocks were measured with a piezoelectric quartz sensor, designed for quasistatic and dynamic tensile and compressive forces ranging from 1 mN to 50 N. It could be proved that pyramidal bodies impact supercritical flow more than cubical bodies of equal projected cross-sectional area do.

DOI:

Year: 2007