Author : National Aeronautics and Space Administration (NASA)
Publisher : Createspace Independent Publishing Platform
ISBN 13 : 9781721941476
Total Pages : 210 pages
Book Rating : 4.9/5 (414 download)
Book Synopsis Supersonic Test of the 10-Inch Bifurcated Two-Stage Supersonic Inlet (Btssi) by : National Aeronautics and Space Administration (NASA)
Download or read book Supersonic Test of the 10-Inch Bifurcated Two-Stage Supersonic Inlet (Btssi) written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-27 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experimental results from testing of a novel supersonic inlet model in NASA Glenn Research Center's 10- by 10-foot supersonic wind tunnel are presented. The patented inlet concept, called Two-Stage Supersonic Inlet (TSSI), incorporates a large cavity, or throat slot, in the supersonic diffuser intended to enhance the stability of the normal shock. The present embodiment of the concept is a bifurcated twin-duct) design. During the course of testing an unusual 'semi-started' mode of operation was encountered. The inlet was able to spill up to 30 percent of the captured airstream without fully expelling the normal shock. In this mode, the total pressure recovery dropped approximately 6 percent without increasing steady-state distortion. Dynamic instrumentation at the cowl lip station indicates the semi-start mode may be a series of unstart/restart cycles with frequency ranging from 0.2 to 20 Hz. Engine face total pressure measurements indicate a modest impact due to this event. However, since the current test article does not have a representative subsonic diffuser (and is in fact separated), it is unclear how this mode of operation would effect an engine. Further investigation of this phenomenon is required before it is fully understood. Prior testing of the TSSI concept allowed extension of fully started inlet operation to regions of significantly reduced supply flow without reducing recovery. The test article was a smaller scale than the present test and was a single duct design. In the present test, the expanded range of stable operation with high recovery was not realized. Carlin, C. M. and Frisch, I. and Kolden, J. J. and Koncsek, J. L. and Marrs, K. J. and Mayer, D. W. and McMahon, S. L. and Milligan, K. H. and Sommerfield, D. M. Glenn Research Center NAS3-25963; WBS-22-714-01-38
