Steady deflection measurements were taken of two identical NASA/Pratt
& Whitney-designed fan blades while they were rotating in
a vacuum in NASA Lewis Research Center's Dynamic Spin Facility.
The one-fifth-scale fan blades, which have a tip diameter of 22
in. and a pinroot retention, are of sparshell construction
and were unducted for this test. The purpose of the test was to
measure the change of the radial deflection of the blade tip and
blade angle at selected radial stations along the blade span with
respect to rotational speed.
The procedure for radial deflection measurement had no precedent
and was newly developed for this test. Radial deflection measurements
were made to assure adequate tip clearance existed between the
fan blades and the duct for a follow-on wind tunnel test. Also,
blade angle deflection measurements were desired before pitchsetting
parts for the wind tunnel test were finish machined. During the
test, laser beams were aimed across the blade path into photodiodes
to give signals that were used to determine blade angle change
or tip radial deflection. These laser beams were set parallel
to the spin axis at selected radial stations.
For the figures, we compared results from the test with analytical predictions made at NASA. The left figure compares measured and calculated values for tip radial deflection at 10,000 rpm for cruise and reverse staggers.1 The right figure shows the measured and calculated change in blade angle versus rotational speed for the cruise stagger measured at three radial stations.
Previous articleLast updated May 5, 1997
Responsible NASA Official:
Gynelle.C.Steele@nasa.gov
216-433-8258
Point of contact for NASA Glenn's Research & Technology reports:
Cynthia.L.Dreibelbis@nasa.gov
216-433-2912
SGT, Inc.
Web page curator:
Nancy.L.Obryan@nasa.gov
216-433-5793
Wyle Information Systems, LLC
