跨临界碳氢二元混合物的水动力学与传热特性实验研究  

Experimental Study on Hydrodynamic and Heat Transfer Characteristics of Binary Mixtures at Tans- and Supercritical Pressures

作　　者：杨竹强[1] 李天卉 高天泽 韩瑞岩 张博[1] 刘峰[1] YANG Zhuqiang;LI Tianhui;GAO Tianze;HAN Ruiyan;ZHANG Bo;LIU Feng(School of Energy and Power Engineering, Dalian University of Technology, Dalian, Liaoning 116024, China)

机构地区：[1]大连理工大学能源与动力学院,辽宁大连116024

出　　处：《西安交通大学学报》2020年第6期140-147,共8页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(51606030);国家科技重大专项资助项目(2017-Ⅲ-0005-0029);中央高校基本科研业务费专项资金资助项目。

摘　　要：针对超燃冲压发动机热防护所采用的再生主动冷却技术中的流动不稳定问题,对亚超临界二元碳氢混合物的流动及传热特性进行了实验研究。基于流动方向对水动力学特性影响的实验结果,即水平管路较竖直管路更容易发生静态不稳定现象,研究了水平管内不同混合比例的二元混合物的水动力学及传热特性。结果显示:流动不稳定起始点(OFI)与换热过程极值点对应,说明水动力学特性与其换热过程具有耦合关系;二元混合物的水动力学特性基本规律与纯物质相同,增加易挥发物的比例会使OFI对应的质量流量向更大的方向移动。通过包含3个对OFI有影响的参数的两组无量纲数对混合物流动不稳定起始点进行线性拟合,得到了混合物的静态不稳定区间的起始边界。此项研究将OFI与传热过程进行耦合分析,对预测混合物的流动不稳定边界以及发动机主动冷却技术的通道设计具有参考价值。To solve the problems of flow instability in regenerative active cooling technology used in the thermal protection of scramjet,the hydrodynamic and heat transfer characteristics of binary hydrocarbons are experimentally studied.Based on experimental results from the influence of flow directions on hydrodynamic characteristics,that is a horizontal tube is more prone to static instability than a vertical tube,the hydrodynamic and heat transfer characteristics of binary mixtures with different mixing ratios in horizontal tubes are studied.The results show that the onset of instability(OFI)corresponds to the extreme value of heat transfer coefficient.It can be concluded that the heat transfer characteristics have coupling relationship with hydrodynamic characteristics;regularities of the hydrodynamic characteristics of binary mixtures are similar with those of pure substance;increasing the blending ratios of volatile substance makes the mass flow rate corresponding OFI move in a larger direction.Two dimensionless numbers containing three parameters affecting OFI are used to obtain the onset instability boundary correlation by liner fitting method for mixtures.The coupling analysis of OFI with the heat transfer process is of guiding significance for predicting the onset instability of mixtures and channel design of the engine active cooling technology.

关 键 词：水动力学 传热 二元混合物 超临界 小通道 

分 类 号：TK24[动力工程及工程热物理—动力机械及工程]