Intrusion of fluid into the inflow branch of a 180/sup 0/-approach mixing tee

Technical Report · Wed Sep 01 04:00:00 EDT 1976

DOI:https://doi.org/10.2172/7322141· OSTI ID:7322141

Debler, W

When the flow rates in the two inlet branches of a 180/sup 0/-approach mixing tee are greatly different, it is possible that the fluid with the high velocity may intrude into the conduit in which the low velocity fluid is flowing. It is shown that such an intrusion should not extend over many pipe diameters. However, if the faster flowing fluid is also the warmer, buoyancy forces may be generated through heat transfer. This in turn may lead to density stratification in what would normally be the cooler fluid's inlet conduit. An extensive eddy develops in this branch of the tee which carries warm fluid many diameters in the upstream direction of the cooler fluid. In the laboratory such an intrusion of warm fluid in the cool fluid branch yields large temperature differences between the top and bottom of the pipe. Such behavior in prototypic systems could produce deleterious thermal stresses. Two mathematical models have been developed to estimate the extent of this density-driven intrusion. One is an inviscid model which incorporates two additional simplifying assumptions to give an initial estimate of the significance of the temperature difference and fluid velocity. This estimate is an initial step in an iterative procedure for a numerical solution scheme. The second method which is presented is a perturbation solution for a low Reynolds number flow. The matching of the solution in two regimes will require the numerical solution of equations to determine the associated coefficients. Once this is done streamline patterns can be drawn for a variety of Froude, Reynolds, and Prandtl numbers.

• Research Organization: Argonne National Lab., IL (USA)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 7322141
• Report Number(s): ANL-CT-76-47
• Country of Publication: United States
• Language: English

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COOLING SYSTEMS
ENERGY TRANSFER
FLOW MODELS
FLOW RATE
FLUID FLOW
FLUID MECHANICS
HEAT TRANSFER
HYDRAULICS
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TEMPERATURE GRADIENTS
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