Recently, Castor Liang's team at the Laser Center of the Hefei Institute of Materials, Chinese Academy of Sciences, carried out a study on corona discharge fluid control and its application in gas laser systems, proposed an electric field-flow field coupling analysis model applicable to multi-needle corona discharge scenarios, revealed the characteristics of the flow rate distribution of the multi-needle electrofluidic pumps and their controlled laws, and designed electrofluidic pumps that can be used for the ultra-compact miniaturization of the gas laser system's non-mechanical medium The design of electrofluidic pump can be used for the non-mechanical medium circulation drive of ultra-compact and miniaturized gas laser system, which breaks through the difficulties in the application of ultra-compact gas laser system under special scenarios. The research results have been published in Physics of Fluids, the top international journal in the field of fluid mechanics, and have been selected as Editor's Pick by the journal.
Traditional gas laser adopts mechanical circulation device to form high-speed medium circulation, which is characterized by large volume, strong vibration and serious noise, and is not suitable for some special application scenarios as well as the application of ultra-compact gas laser system; Electrohydrodynamics (EHD) pump generates "ionized wind" through corona discharge, which has the advantages of light weight, high performance, and low cost. Electrohydrodynamics (EHD) pumps generate "ionic wind" through corona discharge, which has the advantages of light weight, no vibration, no noise, etc., and can replace the traditional mechanical circulating device in the miniaturized gas laser system to expand the applications of gas lasers.
Fig. Computational framework for the edge-value problem of multi-needle EHD pump flow profile
The researchers have studied the flow distribution characteristics of the multi-needle corona discharge EHD pump and its flow rate control problem. Firstly, the nonlinear steady state electrohydrodynamic simplified equations applicable to the multi-needle corona discharge system are derived by establishing a corresponding physical model and a multi-physical field coupling mechanism; secondly, a high-precision and fast numerical calculation algorithm is designed for the edge-value problem of the nonlinear differential equation of the flow velocity profile, which quantitatively calculates the controlled characteristics of the steady-state flow velocity as a function of the variation of the voltage and the electrode spacing parameter.
The results show that the voltage parameter is more dominant than the electrode spacing in the steady state flow rate control of multi-needle EHD pumps, and both the maximum flow rate and the mean flow rate of the system show a superlinear evolution law with voltage control. In the design of the multi-needle EHD pump with 1 cm electrode spacing, a maximum gas flow rate of 0.82 m/s can be obtained by providing an operating voltage of 5000 V, which can meet the requirements of medium circulation in a small gas laser system, satisfy the normal glow discharge at the main electrode, and expand the application of the ultra-compact gas laser system in special scenarios.
Fig. Flow field distribution of the multi-needle EHD system: (a) when the anode voltage is 4000 volts; (b) when the anode voltage is 4500 volts; (c) when the anode voltage is 5000 volts
Jinliang Han, a master's student, was the first author of the paper, and Castor Liang, a researcher, was the corresponding author of the paper. This research was supported by the Youth Innovation Promotion Association of the Chinese Academy of Sciences, the Research Instrumentation and Equipment Development Program of the Chinese Academy of Sciences, and the Youth Team Program of Anguang Institute, Hefei Institute of Materials, Chinese Academy of Sciences.
