Mixing in turbulent flows

Miller, R. S., S. H. Frankel, C. K. Madnia, andP. Givi (1993). Johnson-Edgeworth translation for probability modeling of binary scalar mixing in turbulent flows. Combustion Science and Technology 91, 21-52. 

Dahm, W., Southerland, L., and Su, L., Fully-resolved four dimensional spatio-temporal micromeasurements of the fine scale structure and dynamics of mixing in turbulent flows. AIChE Meet., Miami Beach, FL, paper 262c (1995). 

The inien.se mixing in turbulent flow brings fluid particle.s at different temperatures into close contact, and thus enhances heat transfer. 

Dahm, W.J.A., Southerland, K.B., and Buch, K.A, Direct, high-resolution, fourdimensional measurements of the fine scale structure of Sc l molecular mixing in turbulent flows, Phys. Fluids, A3, 1115 (1991). 

Dahm, W. J. A., K. Southerland, and K. A. Buch. 1991. Direct, High Resolution, Four Dimensional Measurements of the Fine Scale Structure of sc 1 Molecular Mixing in Turbulent Flows, Physics of Fluids, vol. A3, pp. 1115-1127. 

Imperfect meso-mixing in turbulent flow can be important when several reactions take place. In particular, it can influence the selectivity in competitive and competitive-consecutive reactions. 

One of the two most popular approaches to pipeline mixing in turbulent flow involves the use of side injection tees. The other is the use of motionless static mixers (which are discussed later). The most complete work on side tees is by Forney and Lee (1982). They and others have found that the momentum of... 

Pipe reactors can be operated in laminar or turbulent flow. In laminar flow radial diffusivity is molecular only, which is very slow, particularly if the viscosity is high. In turbulent flow the radial fluctuating velocity component produces the radial turbulent diffusivity which is much faster than molecular diffusivity. Many devices have been developed to promote fast radial mixing in laminar flow, such as static mixers, which are discussed below and in Chapter 7. Besides static mixers, a number of methods exist to promote faster radial mixing in turbulent flow, since even in turbulent flow it takes 50 to 100 pipe diameters to achieve... 

The two-film theory still is widely employed to explain mass transfer operations. The boundary between the gas phase and the liquid phase is presumed to consist of a gas film adjacent to a liquid film. Flow in both of these films is assumed to be laminar or stagnant. The main-body gas phase, as well as the main-body liquid phase, are assumed to be completely mixed in turbulent flow so that no concentration gradient exists in the main body of either phase. Further, the solute concentration in the gas film at the interface is assumed to be in equilibrium with the solute concentration in the liquid film at the interface, and there is no resistance to mass transfer across the interface. There is a solute concentration gradient across both the gas film and the liquid film. 

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