The effect of fluid inertia in a squeeze film phenomena is studied numerically. The Navier-Stokes equation and continuity equation are solved directly by using finite difference method and Newton-Raphson method. The method used in this analysis does not depend conventional iteration method or perturbation method and therefore can be applied for wide range of Reynolds number.
The effect of fluid inertia on load carrying capacity and velocity profile are calculated. The analysis is also made for transient problem when squeezing plates start to move or stop suddenly.

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The transformation by a one parameter group, which is used in an analysis of the nonlinear partial differential equations, is facilitated and is generalized by the concept of the differential perturbation equation. The analysis is as follows. The basic equation is differentiated by a parameter, and this equation is formally solved so as to get the differential equation which involves a parameter-derivative. This is called the differential perturbation equation.
Moreover, when this differential perturbation equation is integrated with respect to a parameter under the appropriate initial condition, the transformation which gives the relation between two solutions of the basic equation is obtained.
This theory is applied to a Bäcklund transformation of Burgers equation and a Cole-Hopf transformation.

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A row of vortex rings, which consists of vortex rings at a fixed frequency from a circular orifice, was photographed by a 16 mm cine-camera using the smoke visualization method to study phenomena of the interaction among ring vortices in the vortex row.
The interaction phenomena, observed with increase in velocity at the orifice exit at a constant, vortex generating frequency, were classified into the following four modes ;weak vortex group interaction mode, irregular merging mode, merging mode and passing-through mode. Another interaction phenomenon, which was named as frozen interaction mode, appeared at the same exit velocity as that for merging mode or passing-through mode and at a frequency decreased to a half of that for the two modes.
The first merging or passing-through of two successive vortex rings occurs within the distance nearly one orifice diameter. A kind of feed-back mechanism was proposed to explain the jittering of the location.

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An experimental investigation is made on the relation between ordered motions in the inner layer and large-scale structures in the intermittent region of the outer layer of a turbulent boundary layer. Data from hot-wire anemometers are processed by the conditional sampling technique. It is revealed that both phenomena are originated from vortex-pairs in the boundary layer.

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