Flow visualizatione xperiments were conducted in a water submerged jet to study impingement flow from a long channel with a rectangular exit of aspect ratio five as well as from the one with a circular exit. The flow-types on a large flat plate were observed and classified with the dye-method by mixing blue-black ink with the efflux water. As parameters for the data, the distance from the exit to the plate, the exit velocity( Reynolds number) and the impinging angle caused by rotation of the flat plate around the exit major axis were taken.
It is found that: even at normal impingemen tangle the impingement jet of a shorter distance from the rectangular exit to the flat plate flows only along the directions of the exit minor axis; the change of flow direction on the flat plate highly depends on the distance from the exit to the flat plate and on the exit velocity( Reynolds number); and the spreads on the flat plate become larger in case of the turbulent jet impingement than in case of the laminar one. It is postulated that the overall flow field may be strongly influenced by the entrainment of the turbulent flows as well as the arrangement of the exit and the flat plate.

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This paper deals with the "Continuous Path" control method of a servomechanism with an electro-hydraulic servo valve and a nonsymmetrical cylinder. The nonsymmetrical cylinders have nonlinear characteristics such as piston displacement drift and a difference in speeds of the reciprocating motion due to their nonsymmetrical structure.
Therefore, the application of an optimal servo system to a nonsymmetrical cylinder is difficult by reason of its linear theory. We have eliminated the nonlinearities from this cylinder system by utilizing the velocity feedback method.
Experimental results suggest that the characteristics of the nonsymmetrical cylinder system compensated by velocity feedback are identical with the characteristics of the symmetrical cylinder system regarding the static and dynamic characteristics. In order to realize accurate CP control, an error system is applied to this compensated system. Therefore, it is verified from experimental results that the adoption of this optimal servomechanism serves to eliminate the position deviation, velocity deviation and acceleration deviation together in the steady state. Furthermore, as the parameters of the performance criterion can be denoted by physical coefficients, the relation between these coefficients and the characteristics of this optimal servo on the basis of computer simulations is indicated by using figures. Consequently, the characteristics of this optimal system can be clearly recOgnized, and designed simply.

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This paper deals with transients following the rapid opening of a valve on the upstream sides of fluid lines containing air pocket or liquid column.
Experiments using test pipelines were carried out for the parameter variations in various elements. A theoretical calculation was first performed by applying Runge-Kutta-Gill-methods for the basic equations of lumped-element representation, and then, the pressure surge due to collision of a liquid column was calculated.
The principal points obtained are summarized as follows:
(1) There is a possibility that the pressure surge for an open system with small orifice-pipe cross sectional area ratio A_R is greater than that of a confined system.
(2) Effects such as those of A_R, mass of liquid column and gradient of a pipeline on pressure surge were clarified.
(3) Methods for the approximate calculation of the pressure surge are effective for predicting the transients of fluid lines containing air pocket or liquid column.

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