REG NASA-LLIS-0477-1995 Lessons Learned - IRT Fan Blades.pdf

1、Lessons Learned Entry: 0477Lesson Info:a71 Lesson Number: 0477a71 Lesson Date: 1995-06-12a71 Submitting Organization: LERCa71 Submitted by: Judy TerlepSubject: IRT Fan Blades Description of Driving Event: In the gathering of test data for IRT fan blades, data was extrapolated for test section airspe

2、eds greater than approximately 200 mph using the 20% air blockage models. A desire was expressed for more accurate results of higher test section airspeeds ranging up to 350 mph using the 20% air blockage models. A temporary method was found which would provide the desired airspeed at a relatively l

3、ow cost.This new method consisted of replacing the original fan blades, installed in 1944, with a modified set of spares. The modification included reshaping the blade hubs to an increased angle of attack of 5 degrees.The modified fan blades performance with a reasonable stall margin was calculated

4、to have increased the test section airspeed from 190 mph to 245 mph using the 20% air blockage model. In addition, the drive motor, rated at 5000 hp, only required 2400 hp at 300 mph and maximum rpm. The modified fan blades will take advantage of the remaining horsepower with no alterations of the m

5、otor.Lesson(s) Learned: Modification of IRT fan blades can result in more accurate data or higher test section airspeeds.Recommendation(s): Replace the original IRT fan blades with a modified set of spares.Evidence of Recurrence Control Effectiveness: Provided by IHSNot for ResaleNo reproduction or

6、networking permitted without license from IHS-,-,-Tests were completed using the modified fan blades and their performance was found to be better than initial expectations.Documents Related to Lesson: N/AMission Directorate(s): a71 Exploration Systemsa71 Space Operationsa71 Aeronautics ResearchAddit

7、ional Key Phrase(s): a71 Research & Developmenta71 Test FacilityAdditional Info: Approval Info: a71 Approval Date: 1996-11-06a71 Approval Name: Sell Jamesa71 Approval Organization: 501-4a71 Approval Phone Number: 216-433-8618Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-