Open AccessHydrodynamical problems suggested by Pitot's Tubes
Publication year - 1915
Publication title -
proceedings of the royal society of london. series a, containing papers of a mathematical and physical character
Language(s) - English
Resource type - Journals
eISSN - 2053-9150
pISSN - 0950-1207
DOI - 10.1098/rspa.1915.0043
Subject(s) - pitot tube , bernoulli's principle , mechanics , viscosity , newtonian fluid , tube (container) , dimension (graph theory) , kinematics , physics , mathematics , classical mechanics , thermodynamics , mechanical engineering , engineering , flow (mathematics) , pure mathematics
The general use of Pitot’s tubes for measuring the velocity of streams suggests hydrodynamical problems. It can hardly be said that these are of practical importance, since the action to be observed depends simply upon Bernoulli’s law. In the interior of a long tube of any section, closed at the further end and facing the stream, the pressure must be that due to the velocity ( v) of the stream, i.e. 1/2pv2 , p being the density. At least, this must be the case if viscosity can be neglected. I am not aware that the influence of viscosity here has been detected, and it does not seem likely that it can be sensible under ordinary conditions. It would enter in the combination where v is the kinematic viscosity and l represents the linear dimension of the tube. Experiments directed to show it would therefore be made with small tubes and low velocities.