Brush seal low surface speed hard-rub characteristicsThe bristles of a 38.1-mm (1.5-in.) diameter brush seal were flexed by a tapered, 40-tooth rotor operating at 2600 rpm that provided sharp leading-edge impact of the bristles with hard rubbing of the rotor lands. Three separate tests were run with the same brush accumulating over 1.3 x 10(exp 9) flexure cycles while deteriorating 0.2 mm (0.008 in.) radially. In each, the test bristle incursion depth varied from 0.130 to 0.025 mm (0.005 to 0.001 in.) or less (start to stop), and in the third test the rotor was set 0.25 mm (0.010 in.) eccentric. Runout varied from 0.025 to 0.076 mm (0.001 to 0.003 in.) radially. The bristles wore but did not pull out, fracture, or fragment. Bristle and rotor wear debris were deposited as very fine, nearly amorphous, highly porous materials at the rotor groove leading edges and within the rotor grooves. The land leading edges showed irregular wear and the beginning of a convergent groove that exhibited sharp, detailed wear at the land trailing edges. Surface grooving, burnishing, 'whipping,' and hot spots and streaks were found. With a smooth-plug rotor, post-test leakage increased 30 percent over pretest leakage.
Document ID
19930066264
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Hendricks, Robert C. (NASA Lewis Research Center Cleveland, OH, United States)
Carlile, Julie A. (NASA Lewis Research Center Cleveland, OH, United States)
Liang, Anita D. (NASA Lewis Research Center Cleveland, OH, United States)
Date Acquired
August 16, 2013
Publication Date
June 1, 1993
Subject Category
Mechanical Engineering
Report/Patent Number
AIAA PAPER 93-2534
Meeting Information
Meeting: AIAA, SAE, ASME, and ASEE, Joint Propulsion Conference and Exhibit