Structured Modeling of Bioreactors OTR

It has been mentioned previously (cf. Sect. 3.3.2.3) that micromixing in high-volume reactors can be handled adequately only by structured mixing models. These concepts are observed in case of measuring mixing time in technical scale units (cf. Equ. 3.19 in Table 3.1), but at the same time they exhibit influences on other engineering parameters. 

Many correlations are known for mixing time (e.g.. Brown, 1981 Hugh-mark, 1980 Joshi et al., 1982 Reuss et al., 1980), but these are valid, however, only in bench-scale units. 

An exception are recent data reported concerning gas holdup Sq (Stenberg, 1984)  

as a general conclusion it becomes clear that more sophisticated mixing models are needed for reactor quantification, for example, OTR, on a technical scale (cf. Fig. 3.10, 3.11, and especially Fig. 4.6 and 4.7). 

Basically, two assumptions often used in structured (mixing) modeling are of general importance  

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