Noise Suppression Nozzles for a Supersonic Business Jet

Modern Technologies Corporation (MTC) has conducted some preliminary engine design studies for the Supersonic Business Jet (SBJ) and a preliminary assessment of the engine acoustics. This report summarizes MTC's acoustic sensitivity studies applicable to the SBJ. A range of engine designs is considered, with bypass ratio (BPR) from 0.5 to 2.0 and fan pressure ratio (FPR) from 2.3 to 3.5. Baseline noise levels are established for each engine, so that the required level of suppression is established for that engine concept. The appropriate suppression approach is then established; strategic combinations of technologies are formulated into acoustically robust, "optimum" configurations based on qualitative arguments supported by semi-quantitative analyses. Both conventional and innovative applications of welltested approaches to noise suppression are considered, and the key issues associated with each engine/ suppressor design concept are then discussed.

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