Accession Number : ADA310690

Title :   Investigation of the Effect of Two-Dimensional Cavities on Boundary Layers in an Adverse Pressure Gradient.

Descriptive Note : Doctoral thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : Margason, Richard J.

PDF Url : ADA310690

Report Date : MAR 1996

Pagination or Media Count : 286

Abstract : The present investigation evaluated one aspect of the feasibility of the use of multiple cavities as an airfoil high-lift device. The effects of cavities on the boundary layer characteristics in several pressure gradients were determined experimentally and computationally. Experimentally, it was found that up to four cavities could be deployed with only a small change to the boundary layer profiles downstream of the cavities and without significantly modifying the resultant streamwise pressure distribution. From the computational results for both of the wind tunnel test section lengths used in the experimental investigation, it was found that a grid which provided a converged solution in less than a few hundred iterations was needed before a reasonable comparison with experimental data could obtained. It was also found for these converged solutions that the appropriate grid clustering and density as well as the cell size required for a satisfactory solution was not always apparent before comparing computational results with experimental data. Overall, the investigation results show that a multiple cavity high-lift concept may be feasible.

Descriptors :   *BOUNDARY LAYER, *HIGH LIFT, *CAVITATION, PRESSURE GRADIENTS, THESES, VORTICES, COMPUTATIONAL FLUID DYNAMICS, ANGLE OF ATTACK, FLOW FIELDS, WIND TUNNEL TESTS, AERODYNAMIC DRAG, HYDRODYNAMIC CODES, MACH NUMBER, TWO DIMENSIONAL FLOW, NAVIER STOKES EQUATIONS, FREE STREAM, VISCOUS FLOW, FLOW SEPARATION, WING BODY CONFIGURATIONS, PRESSURE DISTRIBUTION, AERODYNAMIC LIFT, REYNOLDS NUMBER, INCOMPRESSIBLE FLOW, SPOILERS, TRANSONIC FLOW, SHEAR FLOW, BOUNDARY LAYER FLOW, TRAILING CONTROL SURFACES, LEADING EDGE FLAPS.

Subject Categories : Aerodynamics
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE