Characteristics of the Contraction of the Boeing/AFOSR Mach-6 Quiet Tunnel
Abstract
The Boeing/AFOSR Mach-6 Quiet Tunnel continues to be developed to simulate the low noise of the free-flight environment. An investigation of the flow entering the contraction of this facility was necessary to determine whether disturbances in the driver tube are of sufficient amplitude to propagate downstream into the test section of the tunnel. Significant free convection was found in the nominally stagnant pre-run air of the contraction and leads to significant stratification of the air in the driver tube during the run. Two calibration methods were tested and used to compute mass-flow fluctuations in the contraction at a variety of locations and pressures. For regions near the center of the contraction, mass-flow fluctuations of 1.4% were marginally higher than Beckwith's allowable criterion of 1% for settling-chamber noise. This may not preclude quiet flow to the design conditions, since an aluminum surrogate nozzle recently provided quiet flow to 94 psia, 2/3 of the design performance.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 2005
- Accession Number
- ADA441151
Entities
People
- Matthew P. Borg
Organizations
- Purdue University