ワイヤーメッシュスクリーンによる伴流シミュレーションについて

抄録

For the cavitation tests, it is important to reproduce the ship wake distribution of the propeller disk plane as accurately as possible in the cavitation tunnel. When simulating the wake distribution of a ship, two kinds of methods are commonly used; one is the wire mesh screen method which utilizes the speed difference corresponding to the density of its mesh and the other is a dummy model, or the scale model method. The former method is often adopted for the cavitation test, because of the ease of its practical operation in the cavitation tunnel, and the limitation on the size of the cavitation tunnel itself. But, it is troublesome to make the wire mesh screen, because it has been constructed by outdated technology with unreliable results. In order to make the wire mesh screen more efficient, a small wind tunnel having the same profile as the measuring section of the cavitation tunnel has been recently developed, because the ease of the measurement in the wind tunnel. First, this paper introduces the small wind tunnel that has been recently developed, and shows that its performance is sufficient for the wake measurements and is very useful for doing the wake simulation. Second, when measuring the wake distribution of a typical wire mesh screen in both the wind tunnel (in air) and the cavitation tunnel (in water), the results showed that the measurement in both tunnels agreed with each other. Third, the process of the wake simulation on the ship is minutely explained, and it is shown that a center panel is available for the wake simulation on the ships of the V type, and on the ships of the U type, a vortex generator is recommended to adopt for the correct reproduction of the high wake zone. Finally, it was shown that by using the small wind tunnel, the wake simulation could be carried out easily and efficiently, and the final results of the simulation in the wind tunnel agreed with the results measured in the cavitation tunnel.