强迫激励下全混釜内酵母培养系统的混沌行为

The Chaotic Behavior of Saccharomyces Cerevisiae Culture System in CSTR

以全混釜中酵母培养系统为对象,固定外加激励振幅值,改变激励频率,运用数值方法研究了强迫激励下乙醇连续发酵系统中存在混沌的可能性。结果表明,当激励频率 w 小于0.232885时,系统只表现出简单的周期解, 当w 大于0.232885小于0.250185时,系统出现一对周期二吸引子,当 w 增大至0.250185时,系统产生一对周期四吸引子,以后经一系列倍周期分叉出现混沌运动。当w>0.258后,系统出现多种周期窗口。该研究为进一步揭示生化反应系统中更复杂的非线性现象并对通过诱导振荡提高反应器性能提供了理论依据。

The possibility of chaos in S. cerevisiae culture system in CSTR was investigated by means of numerical computation under fixing the amplitude A and changing the frequency w of forced impulse. The results show that only simple periodic solutions exist in the range of 0<w <0.232885. Increasing w to 0.258, the attractor of period 2, 4, 8 and 16 is observed respectively. The further increase of w, the chaos occurs and the evolution process from periodic oscillation to chaos in the continuous culture system is also found. The results obtained in this paper are expected to provide basis for illustrating the more complex nonlinear phenomena and improving the productivity through inducing oscillation.