Structure and Decay Characteristics of Turbulence in the Near and Far-Wake of a Moderately Loaded Compressor Rotor-Blade

Abstract

The wake of a turbomachinery rotor-blade is turbulent, highly three-dimensional, and nonisotropic with appreciable curvature in the trailing-edge and near-wake regions. The characteristics of the turbulence vary considerably with radius, blade loading, free-stream turbulence, Reynolds number, and the rotor-blade geometry. This paper is concerned with the turbulence properties of a moderately loaded compressor blade, particularly near the blade trailing-edge. The tangential variation of the axial, tangential and radial intensities and stresses across the wake, as well as their decay characteristics were measured with a tri-axial hot-wire probe in the rotor frame of reference. The decay of intensities and stresses were found to be very rapid in the trailing-edge and near-wake regions and slow in the far-wake region. The effects of inlet-guide-vane and the hub-wall boundary layers on the rotor wake turbulence spectra are also discussed. Similarity rules for the three components of intensity are also derived and presented in this paper.

An experimental study of three-dimensional characteristics of turbulent wakes of axial compressor rotors

“…The radial component of the turbulence intensity is found to be the highest inside the wakes, and the axial component second, while the tangential component is the lowest. Similar results were obtained by Ravindranath and Lakshrninarayana [5]. Fig.7 shows the distributions of turbulence intensifies across the wakes at near stall condition.…”

Rotor Wake Mixing Effects Downstream of a Compressor Rotor

“…1 and 2. The wake profiles and their decay with streamwise distance near the mid-radius were described in earlier papers (3,4). Radial variations of wake properties and the wake boundary-layer interactions are dealt with in this paper.…”

Experimental Study and Theoretical Prediction of Secondary Flows in a Transonic Axial Flow Compressor

“…The continuous development of highly loaded compressors has revealed the need for a better understanding of the three dimensional nature of the flow. The flow downstream of a rotor has been extensively studied by LAKSHMINARAYANA and his coworkers (1,2,3) as well as by KOOL, DERUYCK and HIRSH (4) who interested themselves mainly in the three dimensional development of the rotor wakes. The importance of viscous effects, especially the ones related with the corner viscous effects, inside blade rows, has been demonstrated by DRING, JOSLIN and HARDIN (5) in a low speed compressor.…”