22nd Congress of International Council of the Aeronautical Sciences, Harrogate, UK, 28 August - 1st September, 2000
Paper ICAS 2000-6.11.2
ACTIVE INLET FLOW CONTROL TECHNOLOGY DEMONSTRATION
J. W. Hamstra (1), D. N. Miller (1), P. P. Truax (1), B. A Anderson, B. J. Wendt
(1) Lockheed Martin Aeronautics Company, USA;
(2) NASA Glenn Research Center, USA
Keywords: inlet, flow control, microvane, microjet
This paper presents results from a joint
Lockheed Martin/NASA Glenn effort to design
and verify an ultra-compact, highly-survivable
engine inlet subsonic duct based on the
emerging technology of Active Inlet Flow
Control (AIFC). In the AIFC concept, microscale
actuation (~mm in size) is used in an
approach denoted ‘secondary flow control’ to
intelligently alter a serpentine duct’s inherent
secondary flow characteristics with the goal of
simultaneously improving the critical systemlevel
performance metrics of total pressure
recovery, spatial distortion, and RMS
turbulence. In this approach, separation
control is a secondary benefit, not a design
requirement. The baseline concept for this
study was a 4:1 aspect ratio ultra-compact
(L/D=2.5) serpentine duct that fully obscured
line-of-sight view of the engine face. At relevant
flow conditions, this type of duct exhibits
excessive pressure loss and distortion because
of extreme wall curvature. Two sets of flow
control effectors were designed with the intent
of establishing high performance levels to the
baseline duct. The first set used two arrays of
36 co-rotating microvane vortex generators
(VGs); the second set used two arrays of 36
micro air-jet (microjet) VGs, which were
designed to produce the same ‘vorticity
signature’ as the microvanes. Optimization of
the microvane array was accomplished using a
Design of Experiments (DOE) methodology to
guide selection of parameters used in multiple
Computational Fluid Dynamics (CFD) flow
solutions. A verification test conducted in the
NASA Glenn W1B test facility indicated low
pressure recovery and high distortion for the
baseline duct without flow control. With
microvane flow control, at a throat Mach
number of 0.60, pressure recovery was
increased 5%, and both spatial distortion and
turbulence were decreased approximately 50%.
Microjet effectors also provided significantly
improved performance over the baseline
configuration.
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