Micro-bubble resistance reduction technology is a method of energysavingthat can be used on ships. In recent years, the concept of it isalso emerging as an attractive method for viscous friction reduction forlow speed ship. A low speed ship model with scale of 1:96 isinvestigated in this paper, high frequency piezoelectric ceramic energytransducers are pasted on the bottom surface of the ship to generatemicro-bubbles in our research, bubble volume fraction and diameter areimportant parameters when study the effects of the micro-bubbles, andthey are easy to control when using the high frequency piezoelectricceramic energy transducers. Model tests are conducted with differentincoming flow velocity, different micro-bubble diameters and differentbubble volume fractions, results showed that resistance reduction rateincreased with the increasing of the bubble volume fraction, thereduction rate also increased with the increasing of the Reynoldsnumber when with high bubble volume fraction, but when the Reynoldsnumber is big enough, the reduction rate varied little even decreased. Inthe range of our experiments, when the viscous drag reduction rate is15%, the corresponding bubble volume fraction is 10% and theincoming flow Reynolds number is1.1×10~6.
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