双CSTR连续发酵及其混沌行为

Fermentation in a System of Two CSTR and Its Behavior of Chaos with Forced Stimulation

运用现代分叉理论,研究了双CSTR耦合系统中乙醇发酵过程中的多定态和振荡现象。计算表明,多定态普遍存在,同时振荡受到多种因素的影响。同单CSTR相比,双CSTR可加强反应深度,大幅度提高产率。最后运用数值方法研究了CSTR连续发酵系统,在强迫激励下(固定周期激励幅值,增加激励频率)由周期解过度到混沌的演化过程,并用时间历程、相图、功率谱和Lyapnov 指数作了验证。

Multiplicty and oscillation are studied for the ethanol fermentation in a model system consisting of two continuous stirred tank bioreactors connected in series. It is demonstrated via computation that multiplicity is universal. And the oscillation is influenced by substrate S 0, volume ratio V 12 and dilution rate D . The performance of the proposed system can be greatly enhanced if the volume ration V 12 is modified appropriately. The behavior of chaos in two CSTR culture system is studied by means of numerical method. Fixing the amplitude and changing the frequency of firced oscillation we find the evolution procedure from oscillations to cascade chaos and then to chaos at last,which is verified by time series, power spectrum and Lyapnov exponents. The study provides important base to find more complicated nonlinear phenomena and control the process of the culture.