Accession Number : AD0282683

Title :   MATERIAL REQUIREMENTS FOR BOUNDARY-LAYER STABILIZING COATINGS-WATER APPLICATION

Corporate Author : RAND CORP SANTA MONICA CALIF

Personal Author(s) : KRAMER,M.O.

Report Date : AUG 1962

Pagination or Media Count : 1

Abstract : INVESTIGATION CONTINUED OF ONE FACET OF A POTENTIALLY IMPORTANT TECHNOLOGICAL ADVANCE IN MINIMIZING SKIN-FRICTION DRAG OF BOTH AIRCRAFT AND HYDROCRAFT. The method investigated consists in favorably modifying the natural boundarylayer flow by means of distributed damping, as opposed to the more widely investigated distributed-suction method. Several features of the distributed-damping method of laminar-flow control are of particular interest for potential vehicular applications: no pumps, associated power sources, or ducts are required within the vehicle; and the stabilizing surface coating applied to the vehicle has a smooth, impermeable surface that is not subject to clogging. The structural material of stabilizing coatings requires primarily a low modulus of elasticity combined with great resiliency, or low inherent damping. Natural rubber is unsatisfactory, since its resiliency is poor at low moduli of elasticity. It is concluded that improved hydraulic performance of the known coating designs can be achieved by using a material with appreciably less inherent damping than rubber, but equal modulus of elasticity. (Author)

Descriptors :   *BOUNDARY LAYER CONTROL, *COATINGS, BIOLOGY, DAMPING, DESIGN, DRAG, ELASTIC PROPERTIES, FLUID MECHANICS, FRICTION, HYDRODYNAMICS, LAMINAR BOUNDARY LAYER, LAMINATES, MECHANICAL PROPERTIES, REDUCTION, SKIN(ANATOMY), STABILIZATION, SURFACE PROPERTIES, TENSILE PROPERTIES, TEST METHODS, TESTS, THEORY, UNDERWATER

Distribution Statement : APPROVED FOR PUBLIC RELEASE