Document
Additional On-Surface and Off-Surface
Aerodynamic Data for Partially-Dressed
Cavity-Closed Nose Landing Gear Benchmark
(PDCC-NLG)
Mehdi R. Khorrami and Dan H. Neuhart
NASA Langley Research Center
Workshop on Benchmark problems for Airframe Noise Computations
(BANC-1)
Stockholm, Sweden, June 10-11, 2010
PDCC - NLG
11 Dynamic Pressure Transducers (1 Roving) ~123 Static Pressure Ports Mobile sensor placed at various hot spots during 2008 entry Unsteady pressures (fixed probes) + PIV data D. H. Neuhart et al. [AIAA 2009-3152] Lower arm Unsteady pressures (mobile sensor) + additional Upper door PIV data provide further insight into flow field Lower drag-link Upper drag-link
Fixed vs. Mobile Sensor
Lower arm Upper door Lower drag-link Upper drag-link
Lower Torque-Arm
Front side Back side Flow
Upper Torque-Arm
Back side Flow
Door Front Side
Door Backside
(Horizontal Rows)
b) a) a b c d d) c)
Door Backside
(Vertical Rows)
a) b) b c a c)
PIV Planes
4 3 1 7 6 5 2 Starboard Port
PDCC vs. FDCO Surface Pressures
Lower arm Upper door Wheel outer Lower drag-link Upper drag-link Lower arm Wheel inner
FDCO vs PDCC Comparison
PDCC FDCO Displayed plane FDCO PDCC PDCC FDCO
X-Z Plane PIV Measurements
6 5 4 3 1 7 2 1) 6) Starboard Port 2) 4) 3)
Summary
Unsteady surface pressures from the mobile sensor confirm the
broadband nature of, and lack of any tonal character in, the
pressure field, corroborating previous results obtained with the
fixed sensors
The shock-strut torque-arm combination produces flow
interactions reminiscent of tandem cylinder flow field
The X-Z PIV planes downstream of the wheels show the wake to
be symmetric
A collective decision must be made as to whether the present
data should be added to the PDCC-NLG dataset
What more can be done and how else can we improve the dataset
for the PDCC-NLG benchmark?