SuperPipe Facility

An experimental facility has been constructed to investigate a fully developed turbulent pipe flow over a large range of Reynolds numbers. In the past many experiments (Nikuradse, 1932; Laufer, 1954 and Townes et al., 1972 to name a few) have been performed on a fully developed turbulent pipe flow because of its simplicity and industrial importance. However, despite the vast amount of data in publication it is difficult to find satisfactory agreement (on friction factor and turbulence intensities for example) between investigations or to find data at very high Reynolds numbers where many industrial systems operate. All of these investigations are lacking in some respect due to either a limited range of Reynolds numbers investigated, an uncertainty in the quality of the inner pipe finish, a questionable accuracy of the measurements, or a lack of experimental proof that the turbulence is fully developed. Therefore, we believe that there is a need for a carefully designed experiment with an emphasis on very accurate measurements over a large range of Reynolds numbers. The lowest Reynolds number investigated will be approximately 5e3, and the highest will exceed 38e6, corresponding to an order of magnitude increase over the highest Reynolds number for mean flow measurements (Nikuradse, 1932), and almost two orders of magnitude over the highest Reynolds number for turbulence measurements (Townes et al., 1972). The measurements will address several fundamental questions in the field of fluid mechanics, including the friction factor and the von Karman's constant dependence on Reynolds number, the inner and outer scaling laws for both the mean and fluctuating velocity field, the behavior of the -1 and -5/3 regions in the turbulence spectra, and the existence of small scale isotropy in a shear flow.