Experimental And Theoretical Study Of Flow Fields Around Ducted Nacelle Models

Author : National Aeronautics and Space Administration (NASA)
Publisher : Createspace Independent Publishing Platform
ISBN 13 : 9781722218584
Total Pages : 24 pages
Book Rating : 4.2/5 (185 download)

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Download or read book Experimental and Theoretical Study of Flow Fields Around Ducted-Nacelle Models written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-03 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: The flow field near four small-scale ducted-nacelle bodies of revolution has been analytically and experimentally studied to determine exterior and interior mass-flow characteristics, and to measure flow-field overpressures generated by the nacelle's forebody shape. Four nacelle models with the same profile, but of different sizes, were used in the study. Shadowgraph pictures showed inlet shocks attached to the cowl lip (indicating unchoked flow) on all four models, at all the test Mach numbers, through an angle of attack range of 0.0 to 6.0 degrees. Pressure signatures measured in the flow field of the largest of the four nacelle models were compared with those predicted by corrected and uncorrected Whitham theory. At separation distances greater than 3.0 to 4.0 inlet diameters, good agreement was found. Poorer agreement was found at extreme near-field separation distances, but this was attributed to pressure-gage limitations and probe-flow field interactions. The overall favorable results supported a conclusion that corrected Whitham theory was sufficiently accurate to make the nacelle-wing interference-lift code useful for sonic-boom analysis and the preliminary design of supersonic-cruise conceptual aircraft. Mack, Robert J. Langley Research Center RTOP 537-07-21-21...