Multiple-jet thermal mixing in a piping tee

Journal Article · Wed Aug 01 04:00:00 EDT 1979 · Nucl. Sci. Eng.; (United States)

OSTI ID:5883190

Lykoudis, P S; Hagar, R C

Piping tees that are used to mix fluid streams at different temperatures are subjected to possibly severe thermal and mechanical stresses. There is reason to suspect that mixing in a piping tee could be improved by injecting the fluid streams into the tee through multiple jets. This paper reports the results of an experimental investigation of the effects of multiple-jet injection on mixing in a piping tee. The experimental work involves the measurement of the temperature fluctuation intensity with a hot-film sensor downstream of a simple 22.22-mm(7/8-in.)-diam tee with mixed multiple-jet injected hot and cold streams of water. The jets were provided by holes drilled in plates that partially blocked the inlet streams; 26 pairs of plates were investigated. The number of holes per plate varied from 1 to 51; the jet diameters ranged from 5 to 68% of the tee diameter. The inlet stream Reynolds number upstream of the jet plates was roughly 15 500 for each stream. The data indicated that the root mean square (rms) temperature fluctuation intensity measured at the tee outlet decreased dramatically as the jet plate cross-sectional area void fraction was decreased. When the jets emanating from the tee plates were misaligned, the reduction of the rms temperature fluctuation was not as high as when the jets were aligned. The rate of decay of the intensity downstream of the tee for most ofthe plates investigated was found to agree well with the -3/4 power decay law predicted by Corrsin's theory of scalar decay. However, unusual features in the intensity decay data were also observed, such as an increase of the intensity several diameters downstream before continuing to decay.

• Research Organization: Purdue Univ., West Lafayette, IN
• OSTI ID: 5883190
• Journal Information: Nucl. Sci. Eng.; (United States), Journal Name: Nucl. Sci. Eng.; (United States) Vol. 71:2; ISSN NSENA
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220200* -- Nuclear Reactor Technology-- Components & Accessories
COOLING SYSTEMS
FLUID FLOW
JETS
MIXING
PIPE FITTINGS
REACTOR COMPONENTS
REACTOR COOLING SYSTEMS
TEMPERATURE DISTRIBUTION
TEMPERATURE GRADIENTS