CIESC Journal ›› 2019, Vol. 70 ›› Issue (9): 3320-3328.DOI: 10.11949/0438-1157.20190313

• Fluid dynamics and transport phenomena • Previous Articles     Next Articles

Modified electrical capacitance tomography linear inversion algorithms for cryogenic fluids two-phase flow measurement

Huangjun XIE1(),Hong CHEN2,Xu GAO2,Xudong ZHENG3,Xiaobin ZHANG1()   

  1. 1. Institute of Refrigeration and Cryogenics, Zhejiang University, Hangzhou 310027, Zhejiang, China
    2. State Key Laboratory of Technologies in Space Cryogenics Propellants, Beijing 100028, China
    3. Micro-Satellite Research Center, Zhejiang University, Hangzhou 310027, Zhejiang, China
  • Received:2019-03-31 Revised:2019-05-28 Online:2019-09-05 Published:2019-09-05
  • Contact: Xiaobin ZHANG

应用于低温流体两相流测量的修正电容层析成像线性反演算法

谢黄骏1(),陈虹2,高旭2,郑旭东3,张小斌1()   

  1. 1. 浙江大学制冷与低温研究所,浙江 杭州 310027
    2. 航天低温推进剂技术国家重点实验室,北京 100028
    3. 浙江大学微小卫星研究中心,浙江 杭州 310027
  • 通讯作者: 张小斌
  • 作者简介:谢黄骏(1994—),男,博士研究生,ponymarine414@foxmail.com
  • 基金资助:
    国家自然科学基金项目(51576169);国家重点研发计划项目(2017YFB0603702)

Abstract:

Based on the dielectric properties of liquid and vapor phases of cryogenic fluids, the modified linear inversion algorithms of electrical capacitance tomography (ECT) are obtained by introducing a correcting deviation into the linear approximate equation of the traditional capacitance-permittivity distribution function. The 8-electrode capacitance tomography sensor was used as the geometric model to simulate the two-phase flow in the liquid oxygen-oxygen tube. The original linear algorithm, the modified linear algorithm and the total variation 1 norm regularity were compared under four different flow patterns. The inversion results of four different flow patterns of original linear algorithms, modified linear algorithms and non-linear algorithms represented by total variation L 1-norm regularization (TV L 1-norm) are compared. The correlation coefficient and image error are taken to measure the quality of the inversion results. The results of numerical experiments show that compared with the original linear algorithms, the quality of the inversion results is greatly improved by the modified linear inversion algorithm. The TV L 1-norm takes more than 10 times as much time as the modified linear inversion algorithm. And when 3% measurement noise is applied, the non-linear algorithm shows strong sensitivity to measurement noise. The modified linear algorithms have better anti-noise ability and accuracy of inversion results.

Key words: two-phase flow, measurement, cryogenic fluids, tomography, linear inversion algorithm

摘要:

针对低温流体液、气两相的介电特性,通过向传统的电容-介电分布函数关系的线性近似方程中引入修正偏量,得到了修正的电容层析成像线性反演算法。以8电极电容层析成像传感器作为几何模型,对液氧-氧气管内两相流进行了模拟,对比了4种不同流型下原始线性算法、修正的线性算法及以全变分1范数正则化为代表的非线性算法的反演结果。采用相关性系数及图像误差定量衡量了反演结果的质量,结果表明,修正线性反演算法显著提升了反演结果的质量,全变分1范数正则化的求解耗时是修正线性算法的10倍以上。当赋以3%测量噪声时,非线性算法表现出对噪声极强的敏感性,修正线性算法具备更好的抗噪能力和反演结果准确性。

关键词: 两相流, 测量, 低温流体, 成像, 线性反演算法

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