Princeton University

research: Princeton High Reynolds Number Test Facility (HRTF)

 

The Supertunnel

 

The Superpipe experiment demonstrated the success of high-pressure air as a working fluid to attain very high Reynolds numbers cost-effectively. In 1998, an ONR-DURIP grant (N00014-98-I-0325) was awarded to construct a wind tunnel based on the same principle. This wind tunnel is called the Princeton/ONR High Reynolds Number Testing Facility -- HRTF, and like the Superpipe it uses air at pressures up to 3,500psi as the working fluid. The primary purpose of the new facility is to study the hydrodynamic forces, moments and flow-fields produced by submarine shapes up to length Reynolds numbers of 175 x 106 (approximately 1/5th full-scale). There are two working sections: each is 8ft long with an internal diameter of 18in. See the most recent slide presentation given about the HRTF to the meeting of the APS Fluid Mechanics Division, New Orleans, November 1999.

The facility will be equipped with a Magnetic Suspension Balance (MSB) to allow measurements free of the interference produced by the support systems usually employed in these applications. Construction is now complete, and we are conducting preliminary tests on flow quality (without MSB, February, 2000). The MSB will be designed, constructed and tested under the supervision of Colin Britcher of ODU. We anticipate that the MSB is expected to be ready for full-scale testing in December 2000.

To the left is an example of a magnetically suspended model. A shuttle model is magnetically suspended in the transparent hexagonal test section of the MIT / NASA Langley 6 Inch MSBS. Massive power supplies are required to drive electromagnets for model position control. A unique electromagnetic position sensor, similar to a linear variable differential transformer, provides five degrees of freedom for the test model. The low speed (Mach 0.5) wind tunnel was hand crafted from mahogany. Aerodynamic forces on the test model are measured by the proportional electrical current used to hold the model in place. The system was built by MIT in the late sixties and was relocated to Langley in the mid eighties. In a joint effort with Old Dominion University in 1992 the MSBS was used to test the aerodynamics of store separation, simulating a bomb released from an aircraft. The system has been donated to Old Dominion University.

 

U.S.S. Albacore

 

Our first model submarine is a 3' version of the U.S.S. Albacore experimental submarine. Fittingly, she was the first Navy-designed vessel with a true submarine hull form and acted as a test bed for numerous submarine developments as well as the model for many future submarines. For more information on the U.S.S. Albacore, visit the U.S.S. Albacore links on the links page in the info section.

 

The Large Cavitation Channel

The Office of Naval Research Broad Agency Announcement 98-025 selected both the HRTF and the LCC for use in 'basic research in turbulence at high Reynolds numbersupporting Department of Navy interests in subsurface hydrodynamics'. Visit the LCC webpage.