Experimental and computational analysis of separation bubble behavior for compressible, steady and oscillatory flows over a NACA 0012 airfoil at M=0.3 and a reynolds number of 540,000
Publisher: Naval Postgraduate School
Published: 1997
Place of publication: Monterey, California
Language: eng
Number of pages: 180
Subjects: VORTEX SHEDDING; STALLING; FLOW SEPARATION; BUBBLES
Description: In this thesis, the separation bubble behavior and its effect on the steady and dynamic stall characteristics of a thin      airfoil in a compressible flow at a transitional Reynolds number was studied. For such flows, laminar separation      occurs near the airfoil leading edge, but turbulent reattachment occurs within a short distance downstream, forming      a separation bubble in the underlying region. Two experimental techniques, point diffraction interferometry (PDI)      and laser doppler velocimetry (LDV), were used to acquire detailed flowfield information that showed the      development of the leading-edge separation bubble and its subsequent bursting at higher angles of attack. The      initiation of the stall process from the leading-edge separation bubble as opposed to trailing-edge flow reversal      pointed to the need for transitional flow analysis. Both in the boundary layer and Reynolds-averaged,      Navier-Stokes (N-S) analysis methods, transition models were incorporated to determine the location and extent of      the transition zone that best modeled the measured separation bubble behavior. Computed results for steady flow      gave remarkable agreement with the measurements.
Notes: Dissertation supervisors, Max F. Platzer, M.S. Chandrasekhara.

AD-A331 903.

Cover title: Experimental ... airfoil (M  =0.3, Rec=540,000).

Dissertation (Ph.D.  in Aeronautical engineering) Naval Postgraduate School, March 1997.

Includes bibliographical references (p. 171-178).

dk/dk cc:9116 12/29/97.