1、Lessons Learned Entry: 0562Lesson Info:a71 Lesson Number: 0562a71 Lesson Date: 1997-09-04a71 Submitting Organization: LARCa71 Submitted by: Harold BeazleySubject: Testing With Removable Shrouds in the LaRC 8-Foot High Temperature Tunnel Description of Driving Event: A model under test in the tunnel
2、required the use of a removable shroud to insulate a sensor from heating while the model was being injected into the tunnel flow. Once the model was in the tunnel flow and was ready to collect data, the shroud was released from the model and ejected from the diffuser of the tunnel. The first test us
3、ed a metal shroud that had been designed with air dams to ensure that it was not aerodynamic. The metal shroud was of sufficient mass and was ejected from the tunnel at sufficient velocity to cause the shroud to travel a long distance placing personnel in its potential path at unacceptable risk. A “
4、catcher screen“ was install but was not successful in capturing the metal shroud. The metal shroud was replaced with a wooden shroud. The wooden shroud provided the needed heat protection for the sensor and upon release, tumbled, contacted the diffuser walls of the tunnel and disintegrated. The piec
5、es of the wooden shroud either came to rest before reaching the catcher screen or were captured by the catcher screenLesson(s) Learned: When an object is ejected into the tunnel air stream, the mass of the object is as critical as its aerodynamic shape. Flight trajectories may vary significantly fro
6、m their theoretical trajectory.Recommendation(s): Ensure that the mass of objects and their credible trajectories are considered prior to placement into the tunnel for testing.Evidence of Recurrence Control Effectiveness: N/AProvided by IHSNot for ResaleNo reproduction or networking permitted withou
7、t license from IHS-,-,-Documents Related to Lesson: N/AMission Directorate(s): N/AAdditional Key Phrase(s): a71 Test & Verificationa71 Test FacilityAdditional Info: Approval Info: a71 Approval Date: 1997-09-04a71 Approval Name: Elijah Kenta71 Approval Organization: 421a71 Approval Phone Number: 757-864-3345Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
