THREE DIMENSIONAL MEASUREMENTS OF INSTANTANEOUS FLOW FIELD IN CORNERS WITH SMOOTH SURFACES UNDER A ZERO PRESSURE GRADIENT

摘要

Three dimensional instantaneous velocity data were taken in a turbulent corner flow with smooth walls under a zero pressure gradient. Experiments were carried out in air with a free stream velocity of 13 m/s and an axial Reynolds number of about 10,000,000. The data were collected using a three-component LDV system that was configured in a nearly orthogonal setup. Measurements were made down to a y+ of approximately 5, and should provide a valuable data set in developing models and predictive codes. Data were collected at two axial locations, 0.93 and 1.26 m measured from the virtual origin. The boundary layer thickness was 20.90 mm and 24.91 mm respectively at these locations. At each position, instantaneous velocity profiles were measured at 6.35, 12.7, 20.6, 41.2, 82.3, 121.9, 164.5, 184.8, and 205.1 mm from the corner. The centerline profiles agree well with classical flat plate data. Three mean velocity and six Reynolds stress components have been calculated. The instantaneous velocity field data set is sufficient to compute higher order correlations. The data will be valuable for development of computer codes and models for heat transfer studies in the internal cooling channels of gas turbine blades and turbine end wall flow and heat transfer studies. An analysis of the data is presented. Future studies will concentrate on one smooth and one rough wall comer flow with favorable and adverse pressure gradients to provide a detailed database for corner flows in complex three dimensional flow fields.