Turbulence burst model

Complicated Reactions and Flow. The ideal turbulence model must deal with multiscale effects within the subgrid model. If there is a delay as velocity cascades to the short wavelength end of the spectrum due to chemical kinetics or buoyancy, for example, the model must be capable of representing this. Otherwise bursts and intermittency phenomena cannot be calculated. 

A model for axial fluctuations stems directly from the equation of motion and can be developed in the usual way by introducing Reynolds decomposition (5). Physically, we visualize a process in which interfacial fluid undergoes a renewal process. Following a burst, a relatively quiescent period of weak turbulence occurs. The time between hursts is controlled by whatever (nonlinear) processes cause the ejection of fluid from the near wall region into the core... 

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