蒸汽射流压力振荡主频分析及强度特性

Frequency analysis and amplitude characteristics of pressure oscillation for steam jet

对蒸汽质量流率298~865kg·m-2·s-1,水温20~70℃的蒸汽射流压力振荡特性进行了实验研究。发现压力振荡特殊主频与汽羽周期性鼓胀和收缩的频率一致。随着凝结形态由在凝结振荡区向稳定凝结区的转变,振荡频率随蒸汽质量流率的增加先增大后减小,振荡主频随冷却水温的升高而下降。振荡幅值的变化与频率变化相反。基于实验结果和分析,给出计算压力振荡量纲1方均根幅值的实验关联式,并在蒸汽质量流率370~865kg·m-2·s-1,水温20~60℃的参数范围内与实验值对比,预测误差在±30%以内。

Experimental investigation on pressure oscillation characteristics for steam jet have been performed in steam mass flux 298—865kg·m-2·s-1,water temperature 20—70 ℃.The dominant frequency agreed with the periodic ballooning and contraction of steam plume.The dominant frequency first increased and then decreased with the increasing water temperature for the condensation region transforming from condensation oscillation region to stable condensation region.The dominant frequency decreased with the increasing water temperature.The variation of dominant frequency was opposite to that of amplitude.Based on the experimental data and analysis,a correlation was given to predict the dimensionless root mean square amplitude.The prediction error was within ±30%in steam mass flux 370—865kg·m-2·s-1,water temperature 20—60℃.