摘要
在航空医学中，人们一直是用气流动压ｑ值的大小来衡量高速气流对人椅系统和人体作用的严重程度。关于动压ｑ值的计算问题，国外有着不同的计算方法，但这些计算方法都不能很好地反应出人椅系统的实际受力情况，特别是在超音速时，其差别就更大。我们通过大量的分析、计算，提出了作用在人椅系统上的动压修正系数Ｋ的半经验公式，并给出了选取修正因子ε，ｆ的方法。在选取ｔ，（ε）的时候，仅需４个不同马赫数的阻力系数实验值。原则上，若实验结果精度较高，对阻力系数实验值的选取并无限制。但当实验数据精度不高，则上述计算的阻力系数的均方根误差就会大些。本方法不仅适用于计算像人椅系统这样的大钝体，而且也适用于计算其它大钝体在任意马赫数范围的阻力系数，其均方根误差小于０．０５。另外，实验数据用半经验公式表示，也便于计算机计算与模拟。
In aviation
medicine,effects of windblast force on human body or air-crew ejection system are usually
estimated by measuring the dynamic pressure q.In this pa-per,a new method of calculation that
reflects actual situation of the dynamic pressure en-countered by aircrew ejection
system,particularly at supersonic speeds was presented.Bas-ing on large scale analyses and
calculations,a semi-empirical mathematic expression of cor-rection coefficient K of dynamic
pressure exerting on aircrew ejection systems was presented and the methods of selecting ε
and f(ε)were proposed.For selecting εand f(ε),only ex-perimental data of drag coefficient at
four different Mach numbers were needed.As a princi-ple,the selection of experimental values
of drag coefficients is free when the experimental valucs,are in high precision,otherwise it’s
root-mean-square error might be considerable.The present method is applicable not only for the
calculation of drag coefficients of large blunt bodies such as aircrew ejection system within
arbitrary Mach number range ,but also good for other large blunt bodies as well,and it’s
root-mean-square error is less than 0.05.In addition,when the experimental values are
expressed as semi-empirical mathematical equation ,it is convenient for computer
programming or simulation under other situations.
出处
《航天医学与医学工程》
CAS
CSCD
1994年第A06期S015-S021,共7页
Space Medicine & Medical Engineering
关键词
弹射座椅
动压
马赫数
气流吹袭
ejection seat,dynamic pressure
calculation,Mach number,blasts
