Aeration‐Induced Circulation from Line Sources. I: Channel Flows

Aeration and mixing of lakes and reservoirs help to control eutrophication and improve water quality. Overall design is often based on economic constraints or hopefully similar situation, with limited knowledge of circulation effectiveness. However, the nature of the vertical flow of water entrained by air plumes rising from manifolds has been studied in detail for other applications and effectively modeled. Here, part of the remaining fluid mechanics of aeration‐induced circulation is described. Experimental studies of the resulting surface flows supplement and extend previous work. Surface velocity decay is described and the circulation cell size from the manifold is shown to be about four times the water depth. Detailed measurements of velocity profiles are presented for a wide range of aeration rates in channels. The influence of aerator design and depth is illustrated, as is the variation of circulation efficiency with aeration rate. A companion paper presents the corresponding buildup of dissolved oxygen.