气固两相流瞬态传热的混沌研究

The Chaos Research of Air Solid Two Phase Flow Transient Heat Transfer

利用瞬态热流计及桥式电路检测技术在电加热圆管上对气固两相流传热过程中的瞬态传热特性进行了试验研究，在此基础上利用混沌理论对气固两相流传热的内在规律进行了分析和探讨，并进一步引入Ｋ熵的概念对气固两相流传热系统的混沌程度进行了定量分析。结果表明，传热信号频率主要在１０Ｈｚ以下，具有宽带频谱特性；固体颗粒浓度增加将使频带范围大、Ｋ熵提高、关联维数增大、系统混沌程度提高，并且传热系数也随关联维数、Ｋ熵及系统混沌程度的增加而增加；固体颗粒浓度增加还将使传热系数脉动幅度和频率提高。计算表明关联维数在０．８～２．５之间。

By detecting technology of transient warm current meter and bridging circuit,this paper studied the characteristic of air solid two phase flow transient heat transfer on electrical heat pipe,discussed the internal law of air solid two phase flow heat transfer by chaos theory,and analyzed countitively chaos degree of air solid two phase flow system by Kolmogrov entropy.The results show that the frequency of heat transfer signal is less than 10Hz and show broadband spectrum,the addition of the concentration of solid particle will increase the range of frequency band,Kolmogrov entropy,chaos degree,correlation dimension,heat transfer coefficient,pulsating amplitude and frequency of heat transfer coefficient.Calculation result shows that correlation dimension is between 0 9~2 5.