Non-isoenergetic Turbulent Jet Mixing in a Constant-Area Duct

A flow model has been devised to deal with the viscid-inviscid interaction of a class of two-dimensional incompressible separated flow problems. It is suggested that the corresponding inviscid flow of these problems is described by the free streamline theory with few unspecified parameters and their values are, in turn, determined by the viscous flow considerations. The problem of a flow past a backward facing step is selected for study in detail. The viscous flow components of turbulent jet mixing, recompression, and reattachment are delineated and studied individually. When they are later combined, it is found that the point of reattachment behaves as a saddle-point-type singularity in the system of differential equations describing the viscous flow process. This feature is employed to the determination of the aforementioned free parameters and thus the establishment of the overall corresponding inviscid flow field. The resulting base pressure coefficient for the specific case agrees reasonably well with the available experimental data. Additional calculations are performed to demonstrate the influence of higher Reynolds numbers and the values of the similarity (or spread rate) parameter σ of the “constant pressure” turbulent jet mixing process. Further studies of redevelopment of the viscous flow after reattachment, the turbulent exchange within the recompression and redevelopment regions, and the effect of wind tunnel-wall interference on the overall flow patterns have been suggested and discussed.

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A general method of designing gas and gas-liquid injectors using laws of turbulent jet mixing

Chemical Engineering & Technology ◽

10.1002/ceat.270160205 ◽

1993 ◽

Vol 16 (2) ◽

pp. 94-101 ◽

Cited By ~ 2

Author(s):

Natti S. Rao ◽

Hans Kremer

Keyword(s):

Turbulent Jet ◽

Jet Mixing ◽

General Method

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Incompressible Jet Mixing in Converging-Diverging Axisymmetric Ducts

Journal of Basic Engineering ◽

10.1115/1.3609555 ◽

1967 ◽

Vol 89 (1) ◽

pp. 210-220 ◽

Cited By ~ 7

Author(s):

P. G. Hill

Keyword(s):

Reynolds Number ◽

Sole Source ◽

Turbulent Jet ◽

Velocity Shear ◽

Jet Mixing ◽

Similarity Relations ◽

Turbulent Reynolds Number ◽

Turbulent Jet Flow ◽

Axisymmetric Tube ◽

Good Agreement

A test has been made of the constant turbulent Reynolds number hypothesis for a turbulent jet flow in a converging-diverging axisymmetric tube. Using the free turbulent jet as the sole source of data for evaluation of the Reynolds number, and velocity shear distributions, the general ducted flow was predicted with the aid of appropriate similarity relations. Calculated results are compared with the extensive and consistent data of Helmbold; good agreement is observed. It is found that the methods of calculation employed can be considerably simplified without large effect on the calculated results. The existence and extent of zones of recirculation are also discussed.

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