Abstract: Micro satellites are widely used in scientific research, traffic navigation, natural disaster forecasting, urban planning, environmental monitoring, national defense security, etc. However, liquefied gas propulsion device, which is often used in micro satellite systems, has a problem that its propellant is not completely vaporized, resulting in a decrease in propulsion performance. To effectively control the gasification process, based on electrical capacitance tomography (ECT) technique, the visualization and void fraction detection method of the liquefied propellant gasification process are presented in this paper. A 6electrode flexible PCB sensor is designed to improve the signal noise ratio of the measurement and reduce the difficulty in processing. Due to the poor image quality of the 6electrode ECT system, a pixel interpolation method is proposed based on linear back projection (LBP) and Tikhonov regularization. The mapping model from gray value to void fraction is also established. Simulation results show that after applying pixel interpolation, the average relative error of the reconstructed image is reduced by 7.72%, and the image quality is significantly improved, with the void fraction measurement error significantly reduced (less than 4.86%). Finally, based on the actual situation of micro satellite propellant gasification, an experiment setup is established, which proves the feasibility of the proposed method.

Key words: micro satellite, liquefied propellant, gas liquid two phase flow, visualization, electrical capacitance tomography, image reconstruction algorithm, interpolation, void fraction