HEAT AND MOMENTUM TRANSFER IN SMOOTH AND ROUGH TUBES AT VARIOUS PRANDTL NUMBERS

Technical Report · Fri Jun 01 04:00:00 EDT 1962

OSTI ID:4778700

Dipprey, D F; Sabersky, R H

Results are presented from an experimental investigation of the relation between heat transfer and friction in smooth and rough tubes. Three rough tubes and one smooth tube were formed from electroplated nickel. The rough tubes contained a close-packed, granular type of surface with roughness-height-to- diameter ratios ranging from 0.0024 to 0.049. Measurements of the heat transfer coefficients (C/sub H/) and the friction coefficients (C/sub F/) were obtained with distilled water flowing through the electrically heated tubes. A Prandtl number range of 1.20 to 5.94 was investigated by adjusting the bulk temperature of the water. Results were obtained for Reynolds numbers from 6 x 10/sup 4/ to 5 x 10/sup 5/ and from 1.4 x 10/sup 4/ to 1.2 x 10/sup 5/ at the lowest and highest Prandtl number, respectively. A similarity rule for heat transfer was used to correlate, interpret, and extend the experimental results. The results were compared with previously existing results, both theoretical and experimental. Increases in C/sub H/ due to roughness of as high as 270% were obtained. These increases were, in general, accompanied by even larger increases in C/sub F/. An exception to this general behavior occurs at high Prandti number in the region of transition between the smooth'' and fully rough'' C/sub F/ characteristic. (auth)

• Research Organization: California Inst. of Tech., Pasadena. Jet Propulsion Lab.
• NSA Number: NSA-17-003107
• OSTI ID: 4778700
• Report Number(s): JPL-TR-32-269; NAS 7-100
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ANALOG SYSTEMS
DISTILLATION
ELECTRICITY
ELECTROPLATING
ENGINEERING AND EQUIPMENT
FLUID FLOW
FRICTION
HEAT TRANSFER
HEATING
MEASURED VALUES
MOMENTUM
NICKEL
PERFORMANCE
PRANDTL NUMBER
REYNOLDS NUMBER
SURFACES
TEMPERATURE
TUBES
TURBULENCE
WATER