Turbulent Boundary Layers on an Airfoil in Several Adverse Pressure Gradients.
Abstract
Turbulent boundary layer profiles in a wide range of adverse pressure gradients were measured using a boundary layer velocity-flow angle measuring probe designed for this experiment. The different pressure gradients were created on a NACA 0012 airfoil by changing the angular orientation of an elliptic cylinder placed near the airfoils trailing edge. Rotating the elliptic cylinder to various angular positions changed the effective angle of attack and camber of the airfoil-ellipse combination thereby creating different pressure distributions about the airfoil. In anticipation of spinning the ellipse to create an unsteady flow in future experiments, this experiment defined the steady state environment. The boundary layer profiles are presented in three different graphical formats; conventional nondimensional plots, profiles in modified Law of the Wall coordinates and Velocity Defect Law graphs. The Law of the Wall was modified to account for longitudinal streamline curvature. Local skin friction coefficients were found using the modified Law of the Wall in the form of a Clauser chart. The boundary layer data was checked for repeatability, consistency and agreement with theory and previous experiments. The final results were deemed excellent.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1978
- Accession Number
- ADA072839
Entities
People
- Richard T. Cervisi
Organizations
- Massachusetts Institute of Technology