液氧传热性能研究

STUDY OF HEAT TRANSFER PERFORMANCE OF LIQUID OXYGEN

关键词:  传热  液氧  液体推进剂火箭发动机  传热系数  计算

Key words:  Heat transfer  Liquid oxygen  Liquid propellant rocket engine  Heat transfer coeff icient  Computation

摘要:

用电加热方法实验研究了超临界压力下临界温度区液氧的传热性能,验证了国内常用的传热准则方程式计算液氧换热的适用性.研究结果表明:用亚临界非等温流体湍流换热公式计算超临界压力下液态氧的传热时,只适用于壁温T_w<200K,液温T_f<140K的传热工况;用谢茨曼提出的临界温度区流体换热公式计算临界温度附近液氧和低温气氧的放热系数时,偏差很大;常用的气体换热公式计算超临界压力下高温气氧的传热,基本合适.文章整理和提出了一个适用于临界温度附近液氧和低温气氧传热计算的新的准则方程式.

Abstract:

Heat transfer performance of liquid oxygen under conditions of critical temperature and supercritical pressure has been studied experimentally by means of electrical heating. The adaptability of criterion equations commonly used at home for calculating the heat transfer performance of L.O.was also examined. The study results show as follows.1. The subcritical,non-isothermal,turbulent heat transfer equation is not suitable for supercritical situation, except for wall temperature TW<200K. and L.O. temperature T1<140K.2. The considerable error would happen when universal heat transfer equation for critical temperature region (relation by Schmzmann, M.) is used for ca-lculating the heat transfer coefficient of L.O.in the vicinity of critical tempera-ture and gas oxygen at low temperature. The calculation conducted with the new criterion relation presented in this paper Nuf = 0.0266Ref0.8Prm0.8(Tw/T1 )-1 is conformed with ihe experimental data very well.3. The popular equation for gas heat exchange can be used for hight-tem-perature gas oxygen under condition of supercritical pressure.