Zero-length inlets for subsonic V/STOL aircraftZero-length inlet performance and associated fan blade stresses were determined during model tests in the NASA-LeRC 9-by 15-foot low-speed wind tunnel. The inlet models, which were installed on a 20-inch diameter fan unit, had different inlet lip contraction ratios as well as unslotted, slotted, and double slotted inlet lips. The inlet angle-of-attack boundaries for onset of flow separation were identified and compared to the operating requirements of several generically different subsonic V/STOL aircraft. The zero-length inlets, especially those with slotted lips, were able to satisfy these requirements without compromising the maximum cowl forebody radius. As an aid to the inlet design process, a unique relationship was established between the maximum surface Mach number associated with the separation boundary and the maximum-to-throat surface velocity ratio.
Document ID
19810057782
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Glasgow, E. R. (Lockheed-California Co. Burbank, CA, United States)
Beck, W. E. (Lockheed-California Co. Burbank, CA, United States)
Woollett, R. R. (NASA Lewis Research Center Cleveland, OH, United States)