NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Collections About News Help Login
Back to Results
Heat transfer in a compact heat exchanger containing rectangular channels and using helium gasDevelopment of a National Aerospace Plane (NASP), which will fly at hypersonic speeds, require novel cooling techniques to manage the anticipated high heat fluxes on various components. A compact heat exchanger was constructed consisting of 12 parallel, rectangular channels in a flat piece of commercially pure nickel. The channel specimen was radiatively heated on the top side at heat fluxes of up to 77 W/sq cm, insulated on the back side, and cooled with helium gas flowing in the channels at 3.5 to 7.0 MPa and Reynolds numbers of 1400 to 28,000. The measured friction factor was lower than that of the accepted correlation for fully developed turbulent flow, although the uncertainty was high due to uncertainty in the channel height and a high ratio of dynamic pressure to pressure drop. The measured Nusselt number, when modified to account for differences in fluid properties between the wall and the cooling fluid, agreed with past correlations for fully developed turbulent flow in channels. Flow nonuniformity from channel-to-channel was as high as 12 pct above and 19 pct below the mean flow.
Document ID
19910018192
Acquisition Source
Legacy CDMS
Document Type
Contractor Report (CR)
Authors
Olson, D. A. (National Inst. of Standards and Technology Gaithersburg, MD, United States)
Date Acquired
September 6, 2013
Publication Date
January 1, 1991
Subject Category
Fluid Mechanics And Heat Transfer
Report/Patent Number
NISTIR-3959
NAS 1.26:188684
NASA-CR-188684
PB91-184804
Accession Number
91N27506
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

Related Records

There are no records associated with this record.
No Preview Available