Submerged Thin Plate Weirs with Unequal Beds

At the time that the study described in themonograph commenced, all of the published research onsubmerged thin plate weirs assumed that the upstreamand downstream beds were at the same level. Inpractice downstream beds may be eroded by the flowover the weir leading to unequal bed levels.Using laboratory models, this study examined thedischarge over submerged weirs with unequal beds. Theresulting flow pattern was shown to be different tothat of the equal bed case. The approach channelFroude Number differs from that of the equivalentequal bed case. The standard formulas derived forsubmerged equally bedded weirs were shown to giveincorrect values.The existing standard formulas for calculatingdischarge over submerged thin plate weirs treatsubmerged flow as a variation of the free modularflow. The later part of the study treats flow over asubmerged thin plate weir as a separate flowcondition and proposes an initial form of a newdischarge formula.

Autorentext

The author is a chartered civil engineer specializing in Water Resources, and is also a lecturer in Mathematics. She took her Ph.D at The University of Auckland, and is a lecturer at AUT University, Auckland New Zealand. This study results from her work as a hydrologist with Strathclyde Regional Council in Scotland.

Klappentext
At the time that the study described in the monograph commenced, all of the published research on submerged thin plate weirs assumed that the upstream and downstream beds were at the same level. In practice downstream beds may be eroded by the flow over the weir leading to unequal bed levels. Using laboratory models, this study examined the discharge over submerged weirs with unequal beds. The resulting flow pattern was shown to be different to that of the equal bed case. The approach channel Froude Number differs from that of the equivalent equal bed case. The standard formulas derived for submerged equally bedded weirs were shown to give incorrect values. The existing standard formulas for calculating discharge over submerged thin plate weirs treat submerged flow as a variation of the free modular flow. The later part of the study treats flow over a submerged thin plate weir as a separate flow condition and proposes an initial form of a new discharge formula.