## APPLICATION OF PIV EXPERIMENT IN FLUID MECHANICS TEACHING OF CENTRIFUGAL PUMP AND DEMONSTRATION OF EXAMPLES1)

LI Hongbin,2), JIANG Shuang, NI Fusheng, GU Lei

College of Mechanical and Electrical Engineering, Hohai University, Changzhou 213022, Jiangsu, China

 基金资助: 1)河海大学创新性教学实验项目资助

Received: 2021-08-27   Revised: 2021-09-1

Abstract

Centrifugal pump is one typical application of fluid mechanics theory. Many textbooks for fluid mechanics include centrifugal pump as an important chapter. When conveying a single medium, the flow in the pump is the compound movement of circular motion and relative motion. When conveying the solid-liquid two-phase, there is also a velocity difference between the two phases, hence the internal flow is very complicated. If these complex fluid movements can be visualized to demonstrate flow pattern, it will be a very good supplement to theoretical teaching, which will strengthen students understanding and consolidate classroom knowledge. For better visualize the internal flow, the pump and pipelines are made of transparent material, hence the impeller and volute area can be viewed without obstruction. Using particle image velocimetry (PIV) technology to capture the internal flow, a single medium or two-phase medium flow can be observed in the impeller observation experiment from a macroscopic perspective, velocity field of single medium and the relative velocity of two-phase medium can be measured locally.

Keywords： centrifugal pump; fluid mechanics; PIV (particle image velocimetry

LI Hongbin, JIANG Shuang, NI Fusheng, GU Lei. APPLICATION OF PIV EXPERIMENT IN FLUID MECHANICS TEACHING OF CENTRIFUGAL PUMP AND DEMONSTRATION OF EXAMPLES1). Mechanics in Engineering, 2022, 44(2): 427-433 DOI:10.6052/1000-0879-21-366

## 2 实验教学设计

### 2.2 实验内容安排

(1)为了让学生有感官上的认知,本次实验先安排了流动现象观察实验,从宏观层面观察输送清水或固液两相时离心泵内部流动情况。

(2)待学生对内部流动有了视觉上的了解后,再对内部流场进行粒子图像测速技术的测量,让学生从微观层面了解内部流动,与课堂知识结合起来,安排2次实验。

2.2.1 输送清水,流体在叶轮中的运动和速度三角形的测量实验

### 图6

$|u|=\frac{\pi n}{30} \sqrt{(X_1-X_0)^{2}+(Y_{1}-Y_{0})^{2}}$

2.2.2 输送固液两相,两相间的相对速度的测量实验

2.3.1 流动现象观察实验

(1)输送清水流动实验

(2)输送两相流动实验

2.3.2 复杂流场测量实验

(1)输送清水流动速度场

(2)输送两相流动速度场

## 3 实验教学成效预期

(1)在离心泵输送实验前,通过离心泵实体模型的讲解,让学生了解离心泵的相关结构、工作原理以及电机、联轴器、输送管道等配套组件,对离心泵的具体使用情况有更全面的了解。

(2)在离心泵输送清水实验时,让学生按兴趣分组,分别根据指导书充分熟悉叶轮调速、管道流量调节、激光发生器的开关、相机拍摄软件的相关操作等工作,以免后续实验过程中出现错误操作。这个实验过程可能要长一点,多做几种工况,增加学生动手能力和团队配合协调能力。

(3)通过做清水和固液两相的输送实验,并加以速度场分析,让学生了解离心泵内流体的运动情况,旋转运动、相对运动和固液两相存在的速度差等,对离心泵的认识会更深,还可以启发相关学生研究的兴趣,后续如果深造的话,可选择类似方向。

## 参考文献 原文顺序 文献年度倒序 文中引用次数倒序 被引期刊影响因子

Xie Cuili, Ni Lingying.

Application of CFD in engineering fluid mechanics class and practice

Mechanics in Engineering, 2017, 39(5):503-505 (in Chinese)

Zhao Junfang.

Reinterpretation on some basic concepts in fluid mechanics

Mechanics in Engineering, 2017, 39(3):296-298 (in Chinese)

Guan Xinlei, Gao Yunpeng, Wang Wei, et al. Mechanics in Engineering, 2021, 43(1):135-138 (in Chinese)

PIV流场测量技术在实验教学中的应用

Guo Chunyu, Sun cong, Zhao Dagang et al.

Application of PIV flow field measurement technology in experimental teaching

Experimental Technology and Management, 2019, 36(3):218-221 (in Chinese)

PIV在本科流体力学实验教学中的应用

PIV在"工程流体力学"教学中的应用研究

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