Re: More Raptor info


Message posted by Thud on February 06, 2007 at 7:21:06 PST:

Nimrod,

Here's what I know: The use of convergent only, or convergent/divergent/vectored nozzles will result in operational conditions where there are complex supersonic shock/expansion flows. Many experimental investigations have shown that these flow conditions generate high noise and the potential for structural interaction with large acoustic fatigue loads in up- and away flight. This interaction involves high amplitude peaks that are related to the jet screech phenomenon. Surface temperature distribution data show the presence of elevated temperatures in regions of high turbulence intensity. At selected combinations of NPR and ground height, resonant conditions have been found which produce amplified, non-linear loads. These loads may damage either the aircraft structure and/or the stores. Research is needed to understand the jet induced noise environment.

Thud


In Reply to: Re: More Raptor info posted by Nimrod on February 05, 2007 at 20:40:34 PST:

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