Accession Number : AD0661070

Title :   VORTEX WAKE ROLLUP AND VORTICITY CONCENTRATION BEHIND AN AIRFOIL.

Descriptive Note : Technical rept.,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE AEROELASTIC AND STRUCTURES RESEARCH LAB

Personal Author(s) : McMahon,Thomas Arthur ; Widnall,Sheila Evans

Report Date : JUN 1967

Pagination or Media Count : 33

Abstract : Some experimental evidence seems to confirm that the near wake problem is basically three-dimensional and should be reexamined as such. A concentration mechanism based on this three-dimensionality is proposed and found to predict a gradient of core circulation which is dimensionally correct and gives realistic answers when specific numerical cases are compared to published experiments. The correlation of experiment with theory involves a uniform translation of the theoretical points a specific distance upstream, implying that rotational fluid in the sheet requires a finite, uniform time to get to the core, no matter which downstream station is considered. A paradox in the role of viscosity in the concentrating mechanism is discussed. (Author)

Descriptors :   (*VORTICES, *WAKE), (*AIRFOILS, VORTICES), THREE DIMENSIONAL FLOW, ROTARY WINGS, AERODYNAMIC CHARACTERISTICS, MATHEMATICAL ANALYSIS, VISCOSITY

Subject Categories : Aerodynamics
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE