The current effort characterizes the details of flow interactions and wake interference effects between two cylinders in a tandem configuration. This setup is representative of several component-level flow interactions that occur when air flows over the main landing gear of aircraft. Such interactions are likely to have a significant impact on the noise radiation associated with the undercarriage. This paper focuses on two-dimensional, time-accurate flow simulations of two distinct tandem cylinder flowregimes, associated with short and intermediate separation distances between the two cylinders. Unsteady Reynolds averaged Navier-Stokes simulations using a two-equation turbulence model run at a Reynolds number of 1:66 105 and a Mach number of 0.166 are presented. Emphasis is placed on understanding both the time-averaged and unsteady flow features between the two cylinders and in the wake of the rear cylinder. Predicted mean-flow quantities and vortex shedding frequencies show reasonable agreement with measured data for both cylinder spacings. Computations for the short separation distance exhibit a nonphysical decay of flow unsteadiness with time; however, the predicted sensitivity of the mean lift coefficient to small variations in the upstream flow angularity explains the asymmetric flowfield observed in the present and previous measurements.
Unsteady flowfield around tandem cylinders as prototype component interaction in airframe noise
Instabiles Strömungsfeld um Tandem-Zylinder als Protoptyp der Komponentenwechselwirkung beim Fluglärm
AIAA Journal (online) ; 45 , 8 ; 1930-1941
2007
12 Seiten, 18 Bilder, 29 Quellen
Article (Journal)
English
Flugzeugzelle , Fluglärm , Strömungsfeld , instabile Strömung , Tandemzylinder , Bauteilgruppierung , Flugzeugfahrwerk , Lärmminderung , numerische Simulation , zweidimensionale Darstellung , Navier-Stokes-Gleichung , Reynolds-Gleichung , Turbulenzmodell , Mach-Zahl , Wirbelablösung , Druckverteilung
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