DID YOU KNOW? DTIC has over 3.5 million final reports on DoD funded research, development, test, and evaluation activities available to our registered users. Click HERE
to register or log in.
Influence of Surface Roughness on Compressor Blades at High Reynolds Number in a Two-Dimensional Cascade.
AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING
Pagination or Media Count:
This is a thesis. A cascade test facility has been established which incorporates sidewall boundary layer control, permitting two-dimensional flow investigation over the center span about 23 the width of the blade of an airfoil in cascade, and an investigation has been conducted to determine the influence of roughness on the airfoil. Two representative compressor profiles, the NACA 64-A905 and 65-A506, with two inch chords and aspect ratios of one were tested at airflow inlet velocities comparable to those axial flow compressors. An Axial Velocity Density Ratio of unity was the criterion used to determine when two-dimensional flow was achieved. Test results indicate that initial small increases of roughness have a much greater effect on blade total pressure loss than do subsequent larger roughness values. A small increase in roughness produces a substantial increase in free stream turbulence with practically no effect on the wake. Further increase in roughness produces a substantial effect on the wake but little effect on the free stream turbulence. Surface roughness is shown to have a much greater influence on blade wake turbulence intensity for the higher camber airfoils tested than for lower camber airfoils. Keywords include Cascade Testing, Two-Dimensional Flow Compressor Blades, Roughness Effects, Boundary Layer.
APPROVED FOR PUBLIC RELEASE