This report summarizes the results of an experimental investigation concerning some of the flow characteristics of the CNR-INSEAN CEIMM water tunnel. The study was intended as a propaedeutic investigation for a wider ONR-funded project aimed at characterizing the behavior of superhydrophobic surfaces, with a focus on their ability to reduce frictional turbulent drag. The purpose of the investigation is twofold. - Firstly, to assess the bulk flow quality of the test-section. Of particular interest here is the ability to reproduce an essentially infinite-field flow stream over the flat surface (this may be hindered by a number of factors, including the presence of a dynamometer shaft - aligned along the longitudinal axis of the facility - which is used for marine propeller testing) as well as the possibility to perform experiments at velocities which are substantially lower than those encountered during routine testing activities (actually, the behavior of hydrophobic surfaces is expected to be investigated for incoming velocities of 1 m/s approximately). - Secondly, to assess the behavior of the flow close to the wall, and in particular to check whether the boundary layer characteristics compare favorably with known literature data.
Using subminiature Pitot tubes to access the mean velocity profile in turbulent boundary layer flows
Edoardo Faiella
2018
Abstract
This report summarizes the results of an experimental investigation concerning some of the flow characteristics of the CNR-INSEAN CEIMM water tunnel. The study was intended as a propaedeutic investigation for a wider ONR-funded project aimed at characterizing the behavior of superhydrophobic surfaces, with a focus on their ability to reduce frictional turbulent drag. The purpose of the investigation is twofold. - Firstly, to assess the bulk flow quality of the test-section. Of particular interest here is the ability to reproduce an essentially infinite-field flow stream over the flat surface (this may be hindered by a number of factors, including the presence of a dynamometer shaft - aligned along the longitudinal axis of the facility - which is used for marine propeller testing) as well as the possibility to perform experiments at velocities which are substantially lower than those encountered during routine testing activities (actually, the behavior of hydrophobic surfaces is expected to be investigated for incoming velocities of 1 m/s approximately). - Secondly, to assess the behavior of the flow close to the wall, and in particular to check whether the boundary layer characteristics compare favorably with known literature data.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.