Numerical Investigation of Electrohydrodynamic (EHD) Flow Control in an S-Shaped Duct

An electrohydrodynamic (EHD) method,which is based on glow discharge plasma,is presented for flow control in an S-shaped duct.The research subject is an expanding channel with a constant width and a rectangular cross section.An equivalent divergence angle and basic function are introduced to build the three-dimensional model.Subsequently,the plasma physical models are simplified as the effects of electrical body force and work (done by the force) on the fluid near the wall.With the aid of FLUENT software,the source terms of momentum and energy are added to the Navier-Stokes equation.Finally,the original performance of three models (A,B and C) is studied,in which model A demonstrates better performance.Then EHD control based on model A is discussed.The results show that the EHD method is an effective way of reducing flow loss and improving uniformity at the duct exit.The innovation in this study is the assessment of the EHD control effect on the flow in an S-shaped duct.Both the parametric modeling of the S-shaped duct and the simplified models of plasma provide valuable information for future research on aircraft inlet ducts.     

航空发动机尾喷流场测试技术研究

在本文中,结合计算机控制系统,研究设计了航空发动机尾喷流场三维测试平台,实现了尾喷流场参数的测量,为尾喷流场特性的研究提供了有效的测试方法,强调了计算机测控系统在航空测试领域的重要性。     

Numerical and experimental investigation of plasma plume deflection with MHD flow control

This paper presents a composite magneto hydrodynamics(MHD) method to control the lowtemperature micro-ionized plasma flow generated by injecting alkali salt into the combustion gas to realize the thrust vector of an aeroengine.The principle of plasma flow with MHD control is analyzed.The feasibility of plasma jet deflection is investigated using numerical simulation with MHD control by loading the User-Defined Function model.A test rig with plasma flow controlled by MHD is established.An alkali salt compound with a low ionization energy is injected into combustion gas to obtain the low-temperature plasma flow.Finally,plasma plume deflection is obtained in different working conditions.The results demonstrate that plasma plume deflection with MHD control can be realized via numerical simulation.A low-temperature plasma flow can be obtained by injecting an alkali metal salt compound with low ionization energy into a combustion gas at 1800–2500 K.The vector angle of plasma plume deflection increases with the increase of gas temperature and the magnetic field intensity.It is feasible to realize the aim of the thrust vector of aeroengine by using MHD to control plasma flow deflection.     

Experimental investigation on plasma jet deflection with magnetic fluid control based on PIV measurement

This paper is devoted to experimentally investigating the influence of magnetic field intensity and gas temperature on the plasma jet deflection controlled by magneto hydrodynamics. The catalytic ionization seed CS_2CO_3 is injected into combustion gas by artificial forced ionization to obtain plasma fluid on a high-temperature magnetic fluid experimental platform. The plasma jet was deflected under the effect of an external magnetic field, forming a thrust-vector effect.Magnesium oxide was selected as a tracer particle, and a two-dimensional image of the jet flow field was collected using the particle image velocimetry(PIV) measurement method. Through image processing and velocity vector analysis of the flow field, the value of the jet deflection angle was obtained quantitatively to evaluate the thrust-vector effect. The variation of the jet deflection angle with the magnetic field intensity and gas temperature was studied under different experimental conditions. Experimental results show that the jet deflection angle increased gradually with a rise in gas temperature and then increased substantially when the gas temperature exceeded 2300 K. The jet deflection angle also increased with an increase in magnetic induction intensity. Experiments demonstrate it is feasible to use PIV test technology to study the thrust vector under magnetic control conditions.     

航空发动机尾喷流场测试技术研究

在本文中,结合计算机控制系统,研究设计了航空发动机尾喷流场三维测试平台,实现了尾喷流场参数的测量,为尾喷流场特性的研究提供了有效的测试方法,强调了计算机测控系统在航空测试领域的重要性.