高超声速飞行器磁控热防护系统建模分析  

Analysis of the magnetohydrodynamic heat shield system for hypersonic vehicles

作　　者：李开[1] 刘伟强[1] 

机构地区：[1]国防科技大学高超声速冲压发动机技术重点试验室,长沙410073

出　　处：《物理学报》2016年第6期216-224,共9页Acta Physica Sinica

基　　金：湖南省自然科学基金(批准号:13JJ2002);国家自然科学基金(批准号:90916018)资助的课题~~

摘　　要：针对高超声速飞行器防热,搭建了螺线管磁控热防护系统的物理模型.采用低磁雷诺数磁流体数学模型,分析了外加磁场强度及磁场形态对磁控热防护效果的影响.对比了三种磁场类型(磁偶极子、螺线管、均布磁场)下磁控热防护效果的差异,分析了螺线管几何参数对磁控热防护效果的影响.研究表明,磁场降低表面热流作用存在"饱和现象";三种磁场形态的磁控热防护能力从小到大依次为磁偶极子、螺线管、均布磁场;相同驻点磁感应强度条件下,增大螺线管半径有利于提高磁控热防护效果,缩短螺线管与驻点距离不利于驻点和肩部防热,螺线管长度对磁控热防护效果影响相对较小.During hypersonic flight, the weakly-ionized plasma layer post shock can be utilized for flow control by externally applying a magnetic field. The Lorentz force, which is induced by the interaction between the ionized air and the magnetic field, decelerates the flow in the shock layer. Consequently, the thickness of the shock layer is increased and the convective heat flux can be mitigated. This so-called magnetohydrodynamic（MHD） heat shield system has been proved to be effective in heat flux mitigation by many researchers.Different from the dipole magnet conventionally used in previous researches on MHD heat shield, a normal columned solenoid-based MHD thermal protection system model is built in this paper. The present numerical analysis is mainly based on the low magneto-Reynolds MHD model, which neglects the induction magnetic field. Hall effect and the ion-slip effect are also neglected here because an insulating wall is assumed. With these hypothesis, a series of axisymmetric simulations on the flow field of Japanese Orbital Reentry Experimental Capsule（OREX） are performed to analyze the influence of different externally applied magnetic fields on the efficiency of MHD thermal protection. First, based on the dipole magnet field, the influence of magnetic induction density is analyzed. Second,differences between the efficiency of MHD thermal protection under three types of magnetic field, namely dipole magnet, solenoid magnet, and uniform magnet field are compared. Finally, the influence of the geometric parameters of solenoid magnet on the MHD thermal protection is analyzed. Results show that, saturation effect exists in the process of MHD heat flux mitigation and it confines the effectiveness of MHD heat shield system. Thermal protection capabilities under three types of magnetic field are ranked from weak to strong as dipole magnet, solenoid magnet, and uniform magnet field. Under the same magnetic induction intensity at the stagnation point, first,the increase of solenoid radius improves its effec

关 键 词：磁流体控制 高超声速飞行器 热防护 螺线管磁铁 

分 类 号：V244.1[航空宇航科学与技术—飞行器设计]