排水管道内湍动能分布特性及影响因素

Characteristics and influencing factors of turbulent kinetic energy distribution in sewers

污水中的污染物在管道输送过程中由于管道壁生物膜的微生物作用而发生降解,生化反应过程取决于物质从水相到生物膜之间的传质过程,传质过程受管道中流态特别是湍流作用的影响较大。采用PIV技术和FLUENT软件模拟下水道流态,重点研究充满度为0.1、0.2、0.3、0.4、0.5和坡度为0.003、0.005、0.008、0.01、0.03时水相中湍动能和湍动耗散率的沿程变化。结果表明,在充满度一定时管壁处的湍动能及湍动耗散率最大,且其随着坡度的增大而逐渐增大;坡度一定时,充满度越大管壁处湍动能及湍动耗散率越大。

Pollutants in sewage degraded during transportation in pipeline because of the microbial reaction in biofilm. Microbial reaction was decided by the transfer process from aqueous phase to biofilm, which was af- fected by flow regime in pipe and especially turbulence. In this study, the PIV technology and FLUENT software were applied to simulate the sewer flow patterns and the changes of turbulent kinetic energy and turbulent dissipa- tion rate along the pipe were researched when depth ratios were 0. 1, 0.2, 0.3, 0.4, 0.5 and slopes were 0. 003, 0. 005, 0. 008, 0.01, 0.03. The results show that the turbulent kinetic energy and turbulent dissipation rate near pipe wall are largest in a certain degree of fullness and increase with the increase of slope. In a certain slope, the greater depth ratio is, the higher turbulent kinetic energy and turbulent dissipation rate are.