A review on CFD simulating method for biogas fermentation material fluid

Fermentation material fluid mixing is an indispensable subsidiary technology for modern biogas engineering, which can increase fermentation efficiency substantially. Taking advantage of computational fluid dynamics (CFD), the flowing progress of biogas fermentation material fluid in the anaerobic digesters can be reappeared, the distribution curve of flow pattern can be obtained, the visualization of flow pattern can be achieved, the features and defect of flow configuration can be differentiated on the basis of the flow pattern visualization. Scholars quantified and evaluated advantages and disadvantages of fermentation material fluid mixing schemes by using CFD and setting the parameters of "poor mixing zone", "dead zone" and so on, which became the important basis of modern biogas engineering design. Meanwhile, the mixing form and running parameters can be excellently designed and thus no longer added at random. On the basis of the classic k-ε model, researchers have developed a variety of improved models, which are more suitable for complex and diverse conditions of biogas fermentation material fluid. In this present study, the applicable algorithm models of various working conditions are proposed after subdivision research. During the first decade of the 21st century, one research upsurge of simulating biogas fermentation material mixing by using the CFD simulation is growing up in the biogas field, which makes a great progress on the aspect of optimal design of digesters shape, mixing form, mixing running parameters and methods of fluid, promotes the research levels of biogas science and becomes one of the most important stage of the biogas science phylogeny. All of these represent the development direction of future, accordingly, the summary of progress related with above research aspects is given in this present study.