热流密度对汽水两相流压力波动特性的影响

实验研究了螺旋管内绝热和沸腾汽液两相流动时压力波动特性。分析了热流密度对压力波动的影响规律。结果表明沸腾时波动的均方根和分形参数（分维数、关联维数和Kolmogorov熵）与绝热两相流明显不同，加热热流密度的大小影响各特征参数的大小及其随干度的变化规律。未考虑热流密度影响的流型图或流型转变准则只能在小热流密度时使用。

Effect of Heat Flux on Fluctuating Pressure in Steam-Water Two-Phase Flow

Experiments are carried out in the present paper to study the feature of pressure fluctuating in helical coil for both adiabatic and boiling steam-water two-phase flows.And the effects of heat flux on the fluctuations are stressed study.It shows that heat flux has great influence on the fluctuation feature.The root mean square (RMS) of the fluctuation process under the condition of low heat flux is similar as that of adiabatic flow,while the RMS of great heat flux differs greatly for that of adiabatic flow.The fractal dimension is close to 1.50 under the condition of great heat flux,which means the pressure fluctuating is approaching stochastic process.The correlation dimension increases with increase of heat flux.The Kolmogorov entropy on the condition of low heat flux is greater than that of adiabatic flow,while the contrary appears under the condition of great heat flux.It can be concluded that the flow pattern map and transition theories for flow patterns on basis of adiabatic flow just can be extrapolated to boiling flow with low heat flux.