含沙高速水流的磨蚀机理和掺气抗磨作用

含沙高速水流易引起过流面材料的磨蚀破坏。本文探讨了泥沙磨蚀机理,提出了影响磨蚀的因素;基于紊流猝发理论,建立了混凝土材料壁面磨蚀率的计算公式;根据试验数据导出了掺气水流中混凝土材料壁面磨损率的经验公式。研究表明,含沙水流对固壁材料的磨蚀率随掺气浓度、材料强度的增大而减小,随水流流速、含沙量的提高而增大。利用掺气可有效地降低过流表面的泥沙磨蚀率。

Mechanism of Abrasion to Material by High-velocity Sediment-laden Flow and Effect of Aeration on Abrasion Resistance

The surface material is liable to abrasion by highvelocity sediment-laden flow.In this paper,the mechanism of sand abrasion is discussed and some effects of significant flow factors on material wear are analyzed;Based on the turbulence theory,formulas are derived for predicting the abrasion rate of concrete material wall surface.Based on the test data and regression analysis,an empirical formula is proposed to estimate the abrasion rate of concrete material for high-velocity sediment-laden and aerated flow.It is indicated that the wear rate is related to air concentration,strength of material,flow velocity and sediment concentration.The method of preventing abrasion with aeration is presented.It is shown that the abrasion rate can be reduced with the help of flow aeration.