The flow conditions through suction and exhaust valves is one of very important problems in Diesel engines, that is not only effective on the supercharging action and the engine power but also on the contamination and durability of these valves.
Using computer, we have introduced a new analytical method to obtain the flow pattern of stream line through suction or exhaust valves, in case of giving the distribution of line of source density on these bodies' surfaces, with assumption of the normal velocity on every surface being zero and also the velocity and pressure at the upper flow satisfactorily apart from the valve parts are given.
For an example, we have calculated and plotted the flow pattern by computer method in case of a suction valve with the lift of 20 mm.
As the experimental investigation of the flow, we have done visualization tests of gas flow through the suction valve using a stream line wind tunnel and these two results obtained the analytical and experimental methods, coincide with each other satisfactorily.

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Titanium thin wall (0.5mmt) tubes have been used especially at air cooling zone of surface steam condensers in replace of aluminium brass tubes. Recently there is clear tendency to apply them for whole tubings for preventing sea water pollution.
This paper reports general properties of titanium, corrosion behavior and overall heat transfer rate of titanium tubes and also refers to the two condensers which they have been applied to in Japan.
Titanium has almost same mechanical and physical properties except Young's modulus, specific weight and heat conductivity with those of copper alloys and stainless steels.
Titanium has excellent corrosion resistance to clean and polluted sea water of high velocity and ammonia attack.
Overall heat transfer rate of titanium tube is rather smaller than that of aluminium brass one with thickness of 1.2mm. However, the rate of titanium tube will overcome that of brass tube in the lapse of time. This is considered to be due to titanium's excellent corrosion resistance and low adhesion to fouling substances in sea water.
The condenser with all titanium tubing at Amagasaki works, Kobe Steel Ltd., has shown excellent heat transfer performance and no trouble since it started.
It may be necessary to dissolve the vibrating problem to apply titanium tubing to ship condenser which has more complex vibrating modes than that of condensers on land.

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As a result of elevating thermal efficiency of machines such as boilers, heat engines, heat exchangers, nuclear reactors, etc., their structural elements are recently often subjected to intensive heat load. This tendency is considered to henceforth become more and more remarkable. Therefore, in estimating a quantity of thermal stress induced in the elements, it is necessary to consider the influence of the temperature dependent properties of the materials by magnifying temperature variation induced in the same structural elements.
This paper is concerned with thermoelastic problems for a slab and a sphere subjected to spherically symmetrical temperature fields exhibiting temperature-dependent properties. Formulae have been derived for thermal stress dealing with arbitrary temperature-variation of the properties.
Furthermore, in order to make clear the way of using the formulae, a calculated example for each body is described.

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