MEASUREMENT OF THE THREE-DIMENSIONAL AERODYNAMICS OF AN ANNULAR CASCADE AIRFOIL ROW (TURBOMACHINERY, ANEMOMETER, FLUID MECHANICS, DOPPLER)

RICHIE CHARLES STAUTER, Purdue University

Abstract

Aerodynamic design systems for turbomachine blade rows, which are evolving from simplified 2-D flow models to fundamentally 3-D models, necessarily use many assumptions. Such flow models must therefore, be validated by correlating their predictions with experimental data. The Purdue Annular Cascade Facility has been used to produce experimental data necessary to more fully understand the fundamentally 3-D nature of a turbomachine blade row flow field, and thus provide a database for flow model validation. The 3-D velocity field in the Purdue Annular Cascade Facility has been measured using a Laser Doppler Anemometer (LDA) which permits non-invasive measurement of the local fluid velocity. A five degree-of-motion traversing system has been designed and fabricated to provide the various LDA probe volume orientations necessary to fully determine the velocity vector at any point in the flow field. Both the traversing system and the data acquisition system are computer-controlled. These systems have been used to investigate the passage flow field for three different incidence angles of the cascade airfoils. Data produced by these experiments indicate significant three-dimensionality of the cascade passage flow field. Strong interaction is indicated between the vortices generated within the passage and the boundary layers on the passage surfaces. These interactions include transport of freestream fluid into the endwall regions and transport of fluid from the endwall regions onto the airfoil suction surface. These effects become more pronounced as the incidence angle increases.

Degree

Ph.D.

Subject Area

Mechanical engineering

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