空气水基CAB-35泡沫黏度特性及水平管流研究

Study on Pressure Drop of Air-Water-Based CAB-35 Foam in Horizontal Pipe Flow

摘要: 管流过程中泡沫流体黏度会随工况变化而变化，准确分析其黏度特性、流动规律及压降特征，对泡沫流体在管流工况应用中具有重要意义。本文以空气水基CAB-35泡沫流体为研究对象，采用室内实验与理论分析相结合的方法，系统开展了该泡沫流体的黏度特性及水平管流特征分析研究。结果表明，空气水基CAB-35泡沫呈现出假塑性流体特征，CAB-35浓度和工况温度对其黏度有显著影响，通过引入无量纲温度修正系数构建了其适配的流变本构模型。水平管流实验发现，其流动过程中主要呈现泡沫波浪流、均相流和段塞流三种流型：基于已构建的泡沫流变本构模型开展压降预测，现有典型的Lockhart-Martinelli (L-M)、均相流和漂移流压降模型预测结果均存在一定偏差，考虑气相流量修正以优化误差相对较小的均相流模型，结果显示优化后的模型预测平均误差降低至9.07%。综合表明，基于泡沫流体流变本构模型优化后的管流压降模型满足工程设计的需要，可为这类泡沫流体在管输相关应用中提供理论支持。

Abstract: During pipeline flow, the viscosity of foam fluid changes with operating conditions. Accurate analysis of its viscosity characteristics, flow laws and pressure drop features are of great significance for the application of foam fluid in pipeline flow conditions. In this paper, air-water based CAB-35 foam fluid is taken as the research object, and a combination of laboratory experiments and theoretical analysis is used to systematically carry out the study on viscosity characteristics and horizontal pipeline flow features of this foam fluid. The results show that the air-water based CAB-35 foam exhibits pseudoplastic fluid characteristics. The CAB-35 concentration and operating temperature have significant effects on its viscosity, and an adapted rheological constitutive model is established by introducing a dimensionless temperature correction coefficient. The horizontal pipeline flow experiments reveal that three main flow patterns, namely foam wavy flow, homogeneous flow and slug flow, are observed during its flow. Based on the constructed foam rheological constitutive model to carry out pressure drop prediction, certain deviations exist in the predictions of the existing typical Lockhart-Martinelli (L-M), homogeneous flow and drift flux pressure drop models. By considering gas flow rate correction to optimize the homogeneous flow model with relatively small errors, the results show that the average prediction error of the optimized model is reduced to 9.07%. The comprehensive analysis indicates that the pipeline pressure drop model optimized based on the foam fluid rheological constitutive model meets the needs of engineering design, and can provide theoretical support for the relevant pipeline transportation applications of such foam fluids.