Three-dimensional flow structure in a narrow gap of a peripheral subchannel model of a fuel assembly: time-resolved tomographic velocity measurements

IF 0.5 4区工程技术 Q4 ENGINEERING, AEROSPACE

Thermophysics and Aeromechanics Pub Date : 2026-06-09 DOI:10.1134/S0869864325050142

M. V. Shestakov

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Abstract

The three-dimensional flow structure in narrow gaps between the rods of nuclear fuel assemblies (FAs) has a decisive impact on the heat and mass transfer coefficients, which, in turn, govern the FA performance. In this study, instantaneous three-dimensional velocity fields in a peripheral subchannel model of a fuel assembly were measured for the first time using time-resolved tomographic particle image velocimetry (TR-Tomo PIV). The experiments were performed at Reynolds number Re = 2100. The TR-Tomo PIV measurements enabled characterization of the three-dimensional flow structure and dynamics in a narrow gap of the peripheral subchannel. Based on the obtained data, the vorticity vector components were evaluated throughout the entire flow volume. It is shown that the key mechanisms, responsible for generating extreme values of streamwise vorticity, are the transverse flow oscillations. These oscillations are quasi-periodic (Sh = 0.091) and alternate with stabilization phases, characterized by a straight-through flow.

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燃料组件外围子通道模型窄间隙中的三维流动结构：时间分辨层析速度测量

核燃料组件窄间隙内的三维流动结构对传热传质系数有决定性的影响，而传热传质系数又决定了核燃料组件的性能。在这项研究中，首次使用时间分辨层析粒子图像测速仪（TR-Tomo PIV）测量了燃料组件外围子通道模型中的瞬时三维速度场。实验在雷诺数Re = 2100下进行。TR-Tomo PIV测量能够表征外围子通道狭窄间隙中的三维流动结构和动力学。根据得到的数据，计算了整个流量内的涡度矢量分量。结果表明，产生向流涡度极值的关键机制是横向流动振荡。这些振荡是准周期的（Sh = 0.091），并与稳定相交替，以直通流为特征。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Thermophysics and Aeromechanics THERMODYNAMICS-MECHANICS

CiteScore

0.90

自引率

40.00%

发文量

审稿时长

>12 weeks

期刊介绍： The journal Thermophysics and Aeromechanics publishes original reports, reviews, and discussions on the following topics: hydrogasdynamics, heat and mass transfer, turbulence, means and methods of aero- and thermophysical experiment, physics of low-temperature plasma, and physical and technical problems of energetics. These topics are the prior fields of investigation at the Institute of Thermophysics and the Institute of Theoretical and Applied Mechanics of the Siberian Branch of the Russian Academy of Sciences (SB RAS), which are the founders of the journal along with SB RAS. This publication promotes an exchange of information between the researchers of Russia and the international scientific community.