This is a theoretical investigation of the dynamics of a tidal current when turbulence is of significance. We take the depth of water to be uniform, and we suppose that the external body forces, the mean velocity of the current, and the statistics of turbulence are uniform over all horizontal planes, though they may vary between the sea surface and the sea bottom. In a natural tidal current there will usually be mean horizontal pressure gradients due to mean surface gradients. In order to maintain a horizontal mean sea surface, we shall suppose these pressure gradients to be replaced by external body forces. In §§ 3–5 we take into consideration both the rotation of the earth and the oscillatory nature of a tidal current. We examine the forces of internal friction, the rates of doing work, and the energy relations, in terms of the statistics of the turbulence. The results are particular cases of those due to Osborne Reynolds (1894) and in fact the forces of internal friction consist largely of the Reynolds shearing stresses. In these sections no new principles are introduced, though most of the particular formulae of §§ 4, 5 do not appear to have been previously put on record.
Wetting of Dehydrated Hydrophilic Pseudomonas fluorescens Biofilms under the Action of External Body Forces
