高拱坝挑跌流非碰撞水垫塘消能形式研究

Study on non-impact energy dissipation of ski-drop flow in plunge pool of high arch dam

在峡谷区修建高坝工程,坝身高水头、大泄量的消能防护是关键技术难题之一。本文通过模型试验和数值模拟,研究了收缩式消能工的作用和分层射流在水垫塘内流动特征与消能机理,论述了坝身分层、多孔、分散泄洪的可能型式及其优缺点。为避免射流水舌碰撞分散引起的溅水雾化问题,通过对坝身表、深孔的不同布置形式,创造性地提出表孔、深孔水舌分层入水非碰撞布局的水垫塘消能方案,和采用收缩式消能工,使表、深孔在横向交错布置,在立面分层泄流,深孔水舌穿过表孔水舌之间的空隙处射出,形成交错入水非碰撞格局的水垫塘消能方案。

The function of contractive type energy dissipaters and the mechanism of energy dissipation of submerged jets in plunge pool with multiple flow layers are investigated by model tests and numerical simulation. On this basis, several possible types of energy dissipater for multiple overflow skip-drops and muhiple deep-level outlets for high arch dams without impaction of jets are discussed. Two optimized schemes are suggested. In the first scheme, the incidence of overflow jets is arranged to the downstream of the incident point of the jets discharged from deep-level outlets in the plunge pool. No impaction of jets will occur. Whereas, in the another scheme, the incident points of overflow jets and those of the jets discharged from deep-level outlets are arranged alternatively in the transverse direction of the plunge pool with the aid of contractive type energy dissipater. The impaction of jets also will not occur. Hopefully, the atomization problem will not happen to both schemes.