Accession Number : AD0655766

Title :   PRACTICAL ASPECTS OF CALCULATING SKIN FRICTION COEFFICIENTS BY COLE'S THEORY OF COMPRESSIBLE TURBULENT FLOWS,

Corporate Author : RAND CORP SANTA MONICA CALIF

Personal Author(s) : Raymond,J. L. ; McGann-Lamar,J. V.

Report Date : JUL 1967

Pagination or Media Count : 57

Abstract : Coles' theory for the turbulent boundary layer in a compressible fluid is used to compute curves of skin friction coefficient versus Reynolds number. The Mach numbers and wall-temperature ratios selected provide sufficient information for rapid estimation of turbulent skin friction drag for flat plates with zero pressure gradient. These results, though limited in scope and unverified experimentally for conditions outside the range of data originally considered by Coles, nevertheless provide the practicing aerodynamicist with a relatively simple means of estimating the flat-plate skin friction for airplane or missile components having compressible turbulent boundary layers. Coles' theoretical hypotheses, partly based on experimental data, may be of significant value in improving upon the more exclusively empirical treatments of the past. While not difficult to interpret, Coles' equations are mathematically complex and contain thought-provoking physical reasoning. In addition to the calculations of skin friction, the study includes a discussion of Coles' classical theory and an interpretation of it for practicing aerodynamicists. The machine program for JOSS, The RAND Corporation's on-line interactive computing system, is included. (Author)

Descriptors :   (*SKIN FRICTION, TURBULENCE), TURBULENT BOUNDARY LAYER, THEORY, REYNOLDS NUMBER, DRAG, AERODYNAMIC CHARACTERISTICS, COMPRESSIBLE FLOW, FLAT PLATE MODELS

Subject Categories : Aerodynamics
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE