• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文会议>Congress of Asia and Pacific Division of International Association of Hydraulic Engineering and Research >AIR TRANSPORT CAUSED BY CHUTE AERATORS
【24h】

AIR TRANSPORT CAUSED BY CHUTE AERATORS

机译：滑槽曝气器引起的空运

获取原文
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Chutes with flow velocities in excess of some 20 m/s are typically prone to cavitation. In order to avoid damages, these flows are aerated using chute aerators. The current literature describes the efficiency of these aerators mainly in terms of the air entrainment coefficient as the ratio of the entrained air and water discharges. However, this is a global coefficient neither specifying the precise air distribution in the flow nor its detrainment rate. As cavitation damages occur along the chute boundaries, the associated air concentration is of prime interest. The present investigation focuses on the flow structure and the air transport downstream of chute aerators. Systematic hydraulic model tests were conducted including a data analysis of the spatial air concentration distribution in the near and the far fields downstream of chute aerators. Based on these and other measurements, general air transport zones were described. Three flow zones were introduced, namely the: (1) Jet zone; (2)Re-attachment and spray zone; and (3) Far-field zone. It was further found that aerators have primarily an effect on the average air concentration, whereas they increase the bottom air concentration only slightly. A large de-aeration gradient was found near the bottom downstream of the re-attachment point. It was concluded that the bottom air concentration downstream of chute aerators is smaller than generally assumed. Nevertheless, these air concentrations obviously suffice to inhibit cavitation damages on spillways equipped with aerators.
机译：流速超过约20米/秒的流动速度通常容易出现空化。为了避免损害，这些流量使用滑槽气炉充气。目前的文献描述了这些曝气器的效率主要根据空气夹带系数作为夹带空气和排水的比率。然而，这是一个全球系数，既不指定流量中的精确空气分布也不是其剥离率。由于沿着斜槽边界发生的空化损坏，所相关的空气浓度是主要的兴趣。本研究侧重于流动曝气器下游的流动结构和空气运输。进行系统液压模型试验，包括在滑槽曝气器下游的近端和远场中的空间空气浓度分布的数据分析。基于这些和其他测量，描述了一般的空气运输区。引入了三个流量区，即：（1）喷射区; （2）重新附着和喷雾区; （3）远场区。进一步发现，曝气器主要对平均空气浓度产生影响，而它们仅略微增加底部空气浓度。在重新附着点的底部附近找到大的脱气梯度。结论是，滑槽曝气器下游的底部空气浓度小于普遍认为。然而，这些空气浓度显然足以抑制装有曝气器的溢出行的空化损失。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号