국내 최대 기계 및 로봇 연구정보

기술보고서

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타이틀	Evaluation of Grid Modification Methods for On- and Off-Track Sonic Boom Analysis
저자	Nayani, Sudheer N.;; Campbell, Richard L.
Keyword	BASE FLOW;; COMPUTATIONAL FLUID DYNAMICS;; GRID GENERATION (MATHEMATICS); LEADING EDGES;; SONIC BOOMS;; SUPERSONIC AIRCRAFT;; TURBULENT FLOW;; UNSTRUCTURED GRIDS (MATHEMATICS); WIND TUNNEL TESTS;; WIND TUNNELS
URL	http://hdl.handle.net/2060/20130003237
보고서번호	AIAA Paper 2013-0798
발행년도	2013
출처	NTRS (NASA Technical Report Server)
ABSTRACT	Grid modification methods have been under development at NASA to enable better predictions of low boom pressure signatures from supersonic aircraft. As part of this effort, two new codes, Stretched and Sheared Grid - Modified (SSG) and Boom Grid (BG), have been developed in the past year. The CFD results from these codes have been compared with ones from the earlier grid modification codes Stretched and Sheared Grid (SSGRID) and Mach Cone Aligned Prism (MCAP) and also with the available experimental results. NASA''s unstructured grid suite of software TetrUSS and the automatic sourcing code AUTOSRC were used for base grid generation and flow solutions. The BG method has been evaluated on three wind tunnel models. Pressure signatures have been obtained up to two body lengths below a Gulfstream aircraft wind tunnel model. Good agreement with the wind tunnel results have been obtained for both on-track and off-track (up to 53 degrees) cases. On-track pressure signatures up to ten body lengths below a Straight Line Segmented Leading Edge (SLSLE) wind tunnel model have been extracted. Good agreement with the wind tunnel results have been obtained. Pressure signatures have been obtained at 1.5 body lengths below a Lockheed Martin aircraft wind tunnel model. Good agreement with the wind tunnel results have been obtained for both on-track and off-track (up to 40 degrees) cases. Grid sensitivity studies have been carried out to investigate any grid size related issues. Methods have been evaluated for fully turbulent, mixed laminar/turbulent and fully laminar flow conditions.