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Turbulent-Spot Growth Characteristics: Wind-Tunnel and Flight Measurements of Natural Transition at High Reynolds and Mach NumbersA series of experiments are described which examine the growth of turbulent spots on a flat plate at Reynolds and Mach numbers typical of gas-turbine blading. A short-duration piston tunnel is employed and rapid-response miniature surface-heat-transfer gauges are used to asses the state of the boundary layer. The leading- and trailing-edge velocities of spots are reported for different external pressure gradients and Mach numbers. Also, the lateral spreading angle is determined from the heat-transfer signals which demonstrate dramatically the reduction in spot growth associated with favorable pressure gradients. An associated experiment on the development of turbulent wedges is also reported where liquid-crystal heat-transfer techniques are employed in low-speed wind tunnel to visualize and measure the wedge characteristics. Finally, both liquid crystal techniques and hot-film measurements from flight tests at Mach number of 0.6 are presented.
Document ID
20070038953
Acquisition Source
Glenn Research Center
Document Type
Conference Paper
Authors
Clark, J. P.
(Oxford Univ. Oxford, United Kingdom)
Jones, T. V.
(Oxford Univ. Oxford, United Kingdom)
LaGraff, J. E.
(Syracuse Univ. NY, United States)
Date Acquired
August 24, 2013
Publication Date
March 1, 2007
Publication Information
Publication: Minnowbrook I: 1993 Workshop on End-Stage Boundary Layer Transition
Subject Category
Aerodynamics
Distribution Limits
Public
Copyright
Public Use Permitted.
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