Internal performance characteristics of thrust-vectored axisymmetric ejector nozzles

Lamb, Milton

A series of thrust-vectored axisymmetric ejector nozzles were designed and experimentally tested for internal performance and pumping characteristics at the Langley research center. This study indicated that discontinuities in the performance occurred at low primary nozzle pressure ratios and that these discontinuities were mitigated by decreasing expansion area ratio. The addition of secondary flow increased the performance of the nozzles. The mid-to-high range of secondary flow provided the most overall improvements, and the greatest improvements were seen for the largest ejector area ratio. Thrust vectoring the ejector nozzles caused a reduction in performance and discharge coefficient. With or without secondary flow, the vectored ejector nozzles produced thrust vector angles that were equivalent to or greater than the geometric turning angle. With or without secondary flow, spacing ratio (ejector passage symmetry) had little effect on performance (gross thrust ratio), discharge coefficient, or thrust vector angle. For the unvectored ejectors, a small amount of secondary flow was sufficient to reduce the pressure levels on the shroud to provide cooling, but for the vectored ejector nozzles, a larger amount of secondary air was required to reduce the pressure levels to provide cooling.

Document ID

19950018918

Acquisition Source

Legacy CDMS

Document Type

Technical Memorandum (TM)

Authors

Date Acquired

September 6, 2013

Publication Date

March 1, 1995

Subject Category

Report/Patent Number

Accession Number

95N25338

Funding Number(s)

Distribution Limits

Public

Work of the US Gov. Public Use Permitted.

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