流线型渐变段及其水力设计

连接渐变段是水工建筑物的重要组成部分。目前国内仍沿用传统的连接渐变段型式,即直线扭曲面或八字墙等,其主要缺点是边界处存在转折点,边界不能与水流流线吻合,易产生折冲水流或脱壁现象,对工程造成不良影响。本文提出反向双圆弧扭曲面和反向双抛物线扭曲面两种新型连接渐变段,并结合试验对其体型、水力特性及水力设计等问题进行了初步研究。结果表明,由于新型连接渐变段的边界为流线型,消除了连接处的转折点,能较好地与水流流线吻合,是理想的连接型式。

Stream Lined Transition Section and Its Hydraulic Design

Connecting transition section is an important part of hydraulic structures.At present,we continue touse the traditional types for connecting the transition section,i.e.straight torsional surfaces or splayedjambs.The main weak points of the traditional types are that at the boundary,there is a kickpoint and it cannot be identical with the flow line,easily forms refracted flow and breaks away from the wall,causingharmful effects to the project,The paper puts forward two new types for connecting the transitional sectionof reversed double are torsional face and reversed double parabolic torsional face and makes preliminaryanalysis on the shape,hydraulic property and hydraulic design through tests.The results shown that it in anideal shape of connection which has eliminated the kickpoint at connecting place and can tally with the flowline due to the stream lined boundary.