Faculty Mentor Name
Michael Fabian
Location
Hazy 132
Start Date
5-7-2016 6:20 PM
End Date
5-7-2016 6:30 PM
Abstract
Rocket nozzles are designed to perform best at high altitudes. They do so by employing a high expansion ratio to properly expand the plumb at altitude. In a standard ground test, the exhaust plumb is overexpanded, meaning the relatively high ambient air pressure restricts the plumbs ability to expand to the edge of the nozzle, thus limiting thrust levels. High Altitude Testing (HAT) facilities are able to simulate altitudes of up to 100,000-ft, some even higher. The blowdown ejector style HAT facility employs the use of supersonic diffusers and ejectors to evacuate air and rocket exhaust out of the test section fast enough to create such low pressures. Many variables contribute to how well these facilities will perform, including geometry of the diffuser sections, working fluid characteristics, and ambient conditions. Using various analytical and numerical models, one can characterize and fabricate such a facility to meet predefined standards.
Design Analysis of a High-Altitude Testing Apparatus
Hazy 132
Rocket nozzles are designed to perform best at high altitudes. They do so by employing a high expansion ratio to properly expand the plumb at altitude. In a standard ground test, the exhaust plumb is overexpanded, meaning the relatively high ambient air pressure restricts the plumbs ability to expand to the edge of the nozzle, thus limiting thrust levels. High Altitude Testing (HAT) facilities are able to simulate altitudes of up to 100,000-ft, some even higher. The blowdown ejector style HAT facility employs the use of supersonic diffusers and ejectors to evacuate air and rocket exhaust out of the test section fast enough to create such low pressures. Many variables contribute to how well these facilities will perform, including geometry of the diffuser sections, working fluid characteristics, and ambient conditions. Using various analytical and numerical models, one can characterize and fabricate such a facility to meet predefined standards.