Influence of casing contouring on flutter boundaries of a jet engine fan

被引：0
作者：
Iseni S. [1 ]
Micallef D. [1 ]
Engelmann D. [1 ]
Mailach R. [2 ]
Nicke E. [3 ]
di Mare F. [1 ]
机构：
[1] Lehrstuhl für Thermische Turbomaschinen und Flugtriebwerke, Institut für Energietechnik, Ruhr-Universität Bochum, IC E2-63, Universitätsstr. 150, Bochum
[2] TU Dresden, Institut für Strömungsmechanik, Dresden
[3] Abteilung Fan und Verdichter, DLR, Institut für Antriebstechnik, Linder Höhe, Cologne
来源：
CEAS Aeronautical Journal | 2019年 / 10卷 / 03期
关键词：
Aeroelasticity; Fan casing optimization; Flutter margin; Influence coefficient method; Transonic stall flutter; Traveling wave method; Unstalled flutter;
D O I：
10.1007/s13272-018-0351-y
中图分类号：
学科分类号：
摘要：
This paper describes a detailed flutter analysis of fan casing contour modifications on a scaled high-speed fan to investigate the influence and effect on flutter boundaries. The flutter analysis focusses on discrete selected members from a previous multidisciplinary study of an automated aero-acoustic optimization with respect to the overall engine performance. The aerodynamic baseline performance of the high-bypass ratio fan is validated with measured rig data using Reynolds-averaged Navier–Stokes (RANS) CFD simulations. Flutter stability predictions are based on the energy method in traveling wave and influence the coefficient formulation using a multi-passage fan assembly in a wide engine operating range. Transonic stall flutter occurs for the first bending mode of blade vibration at part speed, where a few design members show an increased stabilizing aeroelastic behavior especially at approach flight condition. In contrast to that, the results indicate a destabilizing flutter stability effect for certain casing designs at cruise speed related to higher mass flows near choke, which is identified as a transonic unstalled flutter type. Aerodynamic key parameters for the flutter onset mechanism have proved to be the shock/boundary layer interactions in tip region of the fan suction side, which leads to flow separation. A second mechanism is driven by the additional blade vibration in combination with the interaction of shock and tip clearance flow as well as the incoming flow. © 2018, Deutsches Zentrum für Luft- und Raumfahrt e.V.
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页码：805 / 815
页数：10
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