Scroll vortex intakes are hydraulic structures commonly used in water supply, drainage and sewerage systems. Water flows into the intake via an eccentric approach channel and a vortex chamber imparts swirl to the flow, leading to a stable air core vortex along the dropshaft. Although much effort has been devoted to investigate the scroll vortex flow, yet the understanding on its hydraulic characteristics is still far from complete due to a lack of detailed velocity field measurements. This paper presents the first comprehensive measurement of the three-dimensional (3D) flow field of a scroll vortex intake using non-intrusive Laser Doppler Anemometry (LDA). A validated 3D Computational Fluid Dynamics (CFD) model with the Volume-Of-Fluid (VOF) method is developed for interpreting the measurement. It is found that the vortex flow in the scroll chamber resembles a free vortex and the circulation is approximately equal to that at the chamber inlet, with a thin bottom boundary layer. The vortex flow at the bellmouth outlet possesses a circulation constant smaller than that in the chamber, and its vertical velocity component is approximately constant across the flow thickness.

涡旋进水口是供水、排水和污水系统中常用的水工结构。水通过偏心进水通道流入进水口，涡流室使水流产生涡流，从而沿着下降轴形成稳定的空气核心涡流。尽管对涡旋涡流的研究已经付出了很多努力，但由于缺乏详细的速度场测量，对其水力特性的理解还很不完整。本文介绍了使用非侵入式激光多普勒风速测量 (LDA) 对涡旋进气口的三维 (3D) 流场进行的首次综合测量。使用流体体积 (VOF) 方法开发了经过验证的 3D 计算流体动力学 (CFD) 模型，用于解释测量结果。发现涡旋腔内的涡流类似于自由涡流，循环量近似等于腔室入口处的循环量，底部边界层较薄。喇叭口出口涡流的循环常数小于腔室，其垂直速度分量在整个流动厚度上近似恒定。