Tip Vortex and Crenulation Effects in a Compressor Cascade with Moving Endwall

Abstract

The effects of changing Reynolds number and flow coefficients on the velocity and pressure flow fields within a linear cascade with moving endwall were investigated in this experimental thesis. All flow field measurements were taken at a constant compressor blade tip gap clearance of 1.0 % chord and endwall speed of 318.6 ft/s (97.1 m/s), with flow coefficients of 0.40, 0.52, 0.62 and 0.72. All data acquisition occurred in a plane 23 % chord downstream of the trailing edge plane of the linear cascade. Hotwire probes determined the complete passage, three-dimensional fowled behind both crenulated and regular blade geometries. Vector plots showed that the mid-span crenulations aligned the flow axially, increasing the wake mixing and reducing the spanwise flow evident in the regular blade's wake region. A total pressure rake measured the pressure fowled behind the blades, showing that the crenulated blade geometry produced larger, less intense areas of total pressure loss than for the regular blades. Overall, the crenulated blade tested showed equal passage total pressure losses, increased wake mixing, reduced wake deficit and a reduced flow turning angle compared to a regular blade of similar overall dimensions.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1999
Accession Number
ADA361607

Entities

People

  • Barry W. Germain

Organizations

  • Air Force Institute of Technology

Tags

Communities of Interest

  • Air Platforms
  • Materials and Manufacturing Processes
  • Sensors

DTIC Thesaurus Topics

  • Acquisition
  • Air Force
  • Blade Tips
  • Boundary Layer
  • Coefficients
  • Compressor Blades
  • Data Acquisition
  • Fluid Flow
  • Geometry
  • Heat Transfer
  • Measurement
  • Pressure Measurement
  • Spreadsheet Software
  • Three Dimensional
  • Trailing Edges
  • Turbines
  • Two Dimensional

Readers

  • Aerodynamics.
  • Fluid Mechanics and Fluid Dynamics.