轴对称体通气空泡的水动力试验研究

The Experimental Research on The Cavitating Flow Round An Asisymmetric Body with Ventilation

本试验的目的是研究轴对称体在通气空化下从局部空泡发展到超空泡状态过程中对水动力的影响,探讨怎样才能实现空化减阻的问题。根据试验要求及目的我们设计了一雷体模型及一整套的试验装置,并在重力直流式水洞中对模型进行一系列的试验,包括自然空化试验与通气空化试验。试验过程中采用了三分力天平、数据采集/转换卡及计算机记录水动力数据。整个试验过程解决了两个关键问题一是怎样获得稳定的通气量,二是如何进行数据采集处理。采用1127/1128型空气速度校准器的过滤器/调压器组件改装做成一个通气装置解决第一个问题;采用12位16通道的PCL818L型A/D转换卡,用LABVIEW语言编写的实时采样软件来处理数据。根据试验所得到的数据,进行深入的分析,得到了在通气空泡发展到超空泡状态可以大大减小阻力的结论。

An experimental research on the cavitating flow round an axisymmetric body with ventilation were conducted and depicted. The aim is to study the cavitation influences to hydrodynamic forces during the course of ventilated cavitation. The problem of reducing drag by ventilated cavitation was mainly discussed. A model and a set of experimental setting were designed according to the requirement and intention of the experiment, and then several series of experiments were did in a gravity water tunnel. During the courses a three component force balance and a computer based data acquisition system were used to measure the hydrodynamic forces on the model. In the experiment, two key problems were expected to be resolved, one was how to get stable airflow, the other was how to collect and deal with the experimental data correctly. The first problem was solved by using the filter/booster component of 1127/1128 air velocity regulator to refit the ventilated setting. The second problem was solved by adapting 12digit 16 channels A/D convert to collect data and using LabView to program the data processing software. The characteristics of hydrodynamic forces were studied. The conclusion indicated that the drag of axisymmetric body can decrease by using ventilated cavitation, which will be used in some projects.