scope:

Description of Driving Event:

A model under test in the tunnel 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 used 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 "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 pieces of the wooden shroud either came to rest before reaching the catcher screen or were captured by the catcher screen