GLTRS--Glenn
TITLE AND SUBTITLE:
Investigations of Control Surface Seals for Re-Entry Vehicles

AUTHOR(S):
Patrick H. Dunlap, Jr., Bruce M. Steinetz, Donald M. Curry, Jeffrey J. DeMange, H. Kevin Rivers, and Su-Yuen Hsu

REPORT DATE:
July 2002

FUNDING NUMBERS:
WU-706-85-33-00

PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES):
National Aeronautics and Space Administration
John H. Glenn Research Center at Lewis Field
Cleveland, Ohio 44135-3191

PERFORMING ORGANIZATION REPORT NUMBER:
E-13456

SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES):
National Aeronautics and Space Administration
Washington, DC 20546-0001

REPORT TYPE AND DATES COVERED:
Technical Memorandum

SPONSORING/MONITORING AGENCY REPORT NUMBER:
NASA TM-2002-211708
AIAA-2002-3941

SUPPLEMENTARY NOTES:
Prepared for the 38th Joint Propulsion Conference and Exhibit cosponsored by the AIAA, ASME, SAE, and ASEE, Indianapolis, Indiana, July 7-10, 2002. Patrick H. Dunlap, Jr. and Bruce M. Steinetz, NASA Glenn Research Center; Donald M. Curry, NASA Johnson Space Center; Jeffrey J. DeMange, Ohio Aerospace Institute, Brook Park, Ohio; H. Kevin Rivers, NASA Langley Research Center; and Su-Yuen Hsu, Lockheed Martin Space Operations, Hampton, Virginia. Responsible person, Patrick H. Dunlap, Jr., organization code 5950, 216-433-3017.

ABSTRACT:
Re-entry vehicles generally require control surfaces (e.g., rudders, body flaps) to steer them during flight. Control surface seals are installed along hinge lines and where control surface edges move close to the vehicle body. These seals must operate at high temperatures and limit heat transfer to underlying structures to prevent them from overheating and causing possible loss of vehicle structural integrity. This paper presents results for thermal analyses and mechanical testing conducted on the baseline rudder/fin seal design for the X-38 re-entry vehicle. Exposure of the seals in a compressed state at the predicted peak seal temperature of 1900 ¡F resulted in loss of seal resiliency. The vertical Inconel rudder/fin rub surface was re-designed to account for this loss of resiliency. Room temperature compression tests revealed that seal unit loads and contact pressures were below limits set to protect Shuttle thermal tiles on the horizontal sealing surface. The seals survived an ambient temperature 1000 cycle scrub test over sanded Shuttle tiles and were able to disengage and re-engage the tile edges during testing. Arc jet tests confirmed the need for seals in the rudder/fin gap location because a single seal caused a large temperature drop (DT = 1710 ¡F) in the gap.

SUBJECT TERMS:
Seals; Flow; Design; Test; Re-entry vehicle

NUMBER OF PAGES:
30

PDF AVAILABLE FROM URL:
2002/TM-2002-211708.pdf
( 896 KB )
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