Cavity flow characteristics and applications to kidney stone removal
Cavity flow characteristics and applications to kidney stone removal
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腔内流动特性及其在肾结石清除中的应用
DOI：
10.1017/jfm.2020.583
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发表时间：
2020
影响因子：
3.7
通讯作者：
S. Waters
中科院分区：
文献类型：
--
作者：
J. G. Williams;A. A. Castrejón;B. Turney;P. Farrell;S. Tavener;D. Moulton;S. Waters
输尿管镜检查是一种微创的肾结石切除手术。输尿管镜包含一个中空的圆柱形工作通道，被插入病人的肾脏。冲洗靠近镜尖端的肾间隙，清除结石颗粒和碎片，盐水溶液通过工作通道流入。我们考虑了肾盂内灌洗液的流体动力学，这是由通过工作通道的新兴射流和通过通道鞘的回流引起的。将肾盂表示为二维矩形腔，我们研究了流速和腔大小对血流结构和随后碎片清除时间的影响。流体流动用稳定的不可压缩的Navier-Stokes方程来模拟，在入口边界施加泊泽伊剖面来模拟盐水的喷射，在出口处施加零应力条件。由此产生的腔内流型包含多个涡状结构。我们利用互补数值模拟和粒子图像测速实验证明了依赖于流动雷诺数和腔宽高比的多重解的存在性。通过平流-扩散方程的解模拟了初始碎片云的清除，并描述了碎片云在涡旋流中的初始位置和psamclet数对清除时间的影响。只有微弱的扩散，在封闭流线内开始的碎片可能会被困住。我们讨论了一种从漩涡中提取碎片并减少冲洗时间的流动操纵策略。
Abstract Ureteroscopy is a minimally invasive surgical procedure for the removal of kidney stones. A ureteroscope, containing a hollow, cylindrical working channel, is inserted into the patient's kidney. The renal space proximal to the scope tip is irrigated, to clear stone particles and debris, with a saline solution that flows in through the working channel. We consider the fluid dynamics of irrigation fluid within the renal pelvis, resulting from the emerging jet through the working channel and return flow through an access sheath. Representing the renal pelvis as a two-dimensional rectangular cavity, we investigate the effects of flow rate and cavity size on flow structure and subsequent clearance time of debris. Fluid flow is modelled with the steady incompressible Navier–Stokes equations, with an imposed Poiseuille profile at the inlet boundary to model the jet of saline, and zero-stress conditions on the outlets. The resulting flow patterns in the cavity contain multiple vortical structures. We demonstrate the existence of multiple solutions dependent on the Reynolds number of the flow and the aspect ratio of the cavity using complementary numerical simulations and particle image velocimetry experiments. The clearance of an initial debris cloud is simulated via solutions to an advection–diffusion equation and we characterise the effects of the initial position of the debris cloud within the vortical flow and the Péclet number on clearance time. With only weak diffusion, debris that initiates within closed streamlines can become trapped. We discuss a flow manipulation strategy to extract debris from vortices and decrease washout time.
有限元问题几何多重网格求解器的高级实现：在大气建模中的应用
影响因子：
4.1
作者：
Mitchell L
通讯作者：
Mitchell L
影响因子：
23.4
作者：
Scales, Charles D., Jr.;Smith, Alexandria C.;Hanley, Janet M.;Saigal, Christopher S.
通讯作者：
Saigal, Christopher S.