基于能量守恒的四面六边形护岸框架群减速效率推导

The Derivation of Retardation Efficiency of 4-side Hexagon Revetment Framework Group Based on Energy Conservation

4面6边透水框架群的框架尺寸、架空率和长度都直接或间接地影响着其消能减速的效果。在河道中布设框架群对水流会产生阻塞和减速作用,流经框架的水流雷诺数很大,为湍流,属于水力学中的无势有旋流。水力学中涉及湍流的分析计算难以列微分方程,更不可能有解析解。然而,水流的流速减慢必然导致河面抬高,根据水面抬高得到的水头势能与流经框架而带来的阻力损失建立能量守恒方程,便可绕过复杂的水力学计算。通过现有的水力学经验公式,对钢筋混凝土正四面体护岸框架群的水流减速护岸机理进行了理论推导和研究,得出了框架群的减速率η与架空率ε、长a、宽b、铺设长度L的关系式。

The frame size, the overhead rate and the length of 4-side hexagon framework group directly or indirectly affect the effect of energy dissipation to slow down. Layout of framework in the channel can block and slow down the water. If the Reynolds number of water flow through the framework is very large, it is turbulence, belonging to underprivileged hydro cyclone in hydraulics. It is hard to analyze and calculate the turbulence involved in hydraulics in differential equations, but also less likely to have analytical solutions. Water flow slows down, however, inevitably leading to the level of the river. According to the flow of water potential energy and resistance loss, energy conservation equation is established. Through existing hydraulics empirical formula, based on the theoretical derivation of the mechanism of reinforced concrete tetra- hedron frame group protecting banks through flow deceleration, the formula of the deceleration rate and overhead rate, length a, width b, lay- ing length L is obtained.