Design of a High Reynolds Number Testing Facility using compressed air

Abstract

Preliminary design studies are presented for a High Reynolds Number Testing Facility (HRTF) using compressed air as the working fluid. The facility is intended to achieve Reynolds numbers comparable to those experienced by Seawolf class submarines under cruise conditions. 1 Full-scale Reynolds number Here we present a design study for a High Reynolds Number Testing Facility (HRTF) using compressed air as the working fluid. This wind tunnel concept is designed to test vehicles such as submarines at fullscale Reynolds numbers, and its design is largely based on the successful DARPA/ONR Superpipe apparatus built at Princeton to enable accurate pipe flow measurements across a range of Reynolds numbers spanning three orders-of-magnitude. In that facility also, compressed air was chosen as the working fluid to reduce costs. A closed-loop system was built with the test pipe located inside high-pressure piping (see figure 1). The test pipe had a nominal diameter of 129 mm, with a length-to-diameter ratio of 200. For further details of the Superpipe facility, see [1] and [2]. For a submarine of length £, and speed V: the Reynolds numbers based on length is given by To estimate the Reynolds number requirement for the new HRTF, two conditions will be considered, * Associate Fellow, AIAA t Associate Member AIAA ^Copyright © 1997 Alexander J. Smits as shown in table 1. Based on these estimates, we will use Re = 10 as the design point for the HRTF.