在飲用水系統之接管中,接管處常形成凹槽,本文模擬流體在圓直管凹槽中之流態及粒子在管壁上之分佈頻率,流體在凹槽中之流速甚小於在直管內,並且產生一或多個迴流區。當不考慮粒子撞擊管壁又離開之脫附行為,凹槽的存在對粒子分佈影響不大,但若考慮粒子之脫附行為,粒子極易聚集在凹槽處,因而影響飲用水水質。
This paper investigated numerically the fluid flow field over a symmetric cavity in a straight pipe, as well as the frequency distribution of particle deposition on the pipe wall. The cavity flow was much weaker than that in the bulk stream, and exhibited one or several circulation zones. When considering no particle detachment, the existence of a cavity has little effect on the attached particle number distribution. However, if particle detachment is taken into account, the cavity could collect much more particles than the remaining wall regime did, which would lead to a negative impact on drinking water quality.
Relation:
Journal of the Chinese Institute of Chemical Engineers 32(2), pp.177-182