Bending Vibration of a Heated Rod in Quenching Process

加热棒淬火过程中的弯曲振动

基本信息

批准号：
61550147
负责人：
HIHARA Eiji
金额：
$ 1.28万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1986
资助国家：
日本
起止时间：
1986 至 1987
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-61550147/
关键词：
Reflooding Quench Bending Vibration Interfacial Waves Thermal Stress 熱応力

项目摘要

When a vertical heated rod is cooled by subcooled water flowing upward, bending vibration of the rod has been observed under certain conditions. This vibration is caused by the distorted distribution of quench front around the rod and the resultant thermal stress. But the mechanism of the periodical distortion of quench front and the contribution of subcooling of the water temperature to the vibration are not understood. In this study, paying attention to the thermally stratified layers in the cooling water, the relation between the bending vibration and the gravity waves on the interface separating two layers with different temperatures was investigated.The formation of the thermally stratified layers in the water was hydrodynamically investigated. From a numerical simulation, circulation flow is induced above the quench front by the steam flow of film boiling, and heat transmitted from the rod to the water is confined in the circulation flow. Consequently, the temperature of the upper region becomes saturated, and that of the lower region is kept subcooled. The interface usually locates near the quench front.Frequency of the gravity waves on the interface of two layers in a concentric annular conduit was theoretically analyzed. To confirm the hypothesis that the waves on the interface induce the distorted distribution of quench front, various experiments were performed. Influences of the water temperature, water flow rate, and initial rod temperature on the frequencies were measured. The calculated frequencies of gravity waves reasonably agree with those of bending vibration. The marginal boundaries of the onset of bending vibration were obtained experimentally.

当垂直加热的棒被向上流动的过冷水冷却时，在一定条件下观察到棒的弯曲振动。这种振动是由杆周围淬火前沿的扭曲分布以及由此产生的热应力引起的。但淬火前沿周期性畸变的机理以及水温过冷对振动的贡献尚不清楚。在这项研究中，关注冷却水中的热分层层，研究了不同温度的两层之间的界面上的弯曲振动和重力波之间的关系。水中热分层层的形成是流体动力学的。调查了。根据数值模拟，薄膜沸腾的蒸汽流在淬火前沿上方引起循环流，并且从杆传递到水的热量被限制在循环流中。因此，上部区域的温度变得饱和，而下部区域的温度保持过冷。该界面通常位于淬火前沿附近。对同心环形管道中两层界面上的重力波频率进行了理论分析。为了证实界面上的波引起淬火前沿扭曲分布的假设，进行了各种实验。测量了水温、水流量和初始棒温度对频率的影响。重力波的计算频率与弯曲振动的频率相当一致。弯曲振动开始的边缘边界是通过实验获得的。