국내 최대 기계 및 로봇 연구정보

기술보고서

기술보고서 게시판 내용
타이틀	Computational Assessment of the Aerodynamic Performance of a Variable-Speed Power Turbine for Large Civil Tilt-Rotor Application
저자	Welch, Gerard E.
Keyword	AERODYNAMIC CHARACTERISTICS;; COMPUTATIONAL FLUID DYNAMICS;; LOW PRESSURE;; NAVIER-STOKES EQUATION;; REYNOLDS AVERAGING;; ROTARY WINGS;; ROTORS;; TAKEOFF;; THREE DIMENSIONAL MODELS;; TILT ROTOR AIRCRAFT;; TURBINES
URL	http://hdl.handle.net/2060/20110023758
보고서번호	NASA/TM-2011-217124
발행년도	2011
출처	NTRS (NASA Technical Report Server)
ABSTRACT	The main rotors of the NASA Large Civil Tilt-Rotor notional vehicle operate over a wide speed-range, from 100% at take-off to 54% at cruise. The variable-speed power turbine offers one approach by which to effect this speed variation. Key aero-challenges include high work factors at cruise and wide ࿈ to 60 deg.) incidence variations in blade and vane rows over the speed range. The turbine design approach must optimize cruise efficiency and minimize off-design penalties at take-off. The accuracy of the off-design incidence loss model is therefore critical to the turbine design. In this effort, 3-D computational analyses are used to assess the variation of turbine efficiency with speed change. The conceptual design of a 4-stage variable-speed power turbine for the Large Civil Tilt-Rotor application is first established at the meanline level. The design of 2-D airfoil sections and resulting 3-D blade and vane rows is documented. Three-dimensional Reynolds Averaged Navier-Stokes computations are used to assess the design and off-design performance of an embedded 1.5-stage portion-Rotor 1, Stator 2, and Rotor 2-of the turbine. The 3-D computational results yield the same efficiency versus speed trends predicted by meanline analyses, supporting the design choice to *****ute the turbine design at the cruise operating speed.