Effect of heating and inlet geometry on the fully developed pressure drop in the transition region of a horizontal tube

Book · Tue Dec 31 04:00:00 EST 1996

OSTI ID:428146

Tam, L M; Ghajar, A J ^[1]

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1. Oklahoma State Univ., Stillwater, OK (United States). School of Mechanical and Aerospace Engineering

Pressure drop measurements were made with a differential pressure transducer in the fully developed region of a horizontal circular straight tube with reentrant, square-edged, and bell-mouth inlets under isothermal and non-isothermal (uniform wall heat flux) flow conditions. The isothermal fully developed skin friction coefficients showed that the range of Reynolds number values for which transition flow exists is about 2,900--3,500 for the reentrant inlet, 3,100--3,700 for the square-edged inlet, and 5100--6100 for the bell-mouth inlet. Different heat fluxes were applied to the test section in order to investigate the effect of heating on the skin friction coefficient. The results indicated that the value of fully developed skin friction coefficient increased with an increase in the heating rate for a fixed Reynolds number. Due to the presence of secondary flow, the effect of heating on the skin friction coefficient is significant in the laminar and transition regions. This increase in skin friction coefficient causes an increase in the lower and upper limits of the isothermal transition boundaries. Available correlations for prediction of non-isothermal fully developed skin friction coefficients are compared with the experimental data. Correlations for prediction of the non-isothermal fully developed skin friction coefficients in the laminar and transition regions for the three inlets are recommended.

• OSTI ID: 428146
• Report Number(s): CONF-960815--; ISBN 0-7918-1506-4
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
CONFIGURATION
EXPERIMENTAL DATA
FRICTION FACTOR
LAMINAR FLOW
OPENINGS
PRESSURE DROP
TRANSITION FLOW
TUBES