微泡減阻技術實用化之研究

Abstract

節能減碳是目前世界各國的重要課題，在世界80%貿易運輸 依賴海運的情況下，若能減少船舶阻力，提高能源使用效率，對 節能減碳便能有不小貢獻。本研究為在船模上開發具有潛力與潔 淨的微泡減阻技術研究，開發出可應用於船模的微泡減阻技術。 本研究首先使用三種微泡產生方式來進行實驗： (1)針孔微 泡產生方式、(2)滷化技術及(3)透氣材微泡產生方式。針孔微泡 產生方式會產生氣體堆積現象，沒有使用於減阻實驗。將滷化技 術及透氣材於拖曳水槽中進行平板減阻實驗，實驗結果發現透氣 材噴氣時的平板減阻效果明顯優於滷化技術。在拖曳速度3.6m/s 時有最佳減阻效果31.6%。因此本研究選擇了透氣材來應用在船 模上，在船模的底部分別裝設三塊透氣材。實驗的結果顯示三塊 透氣材共同噴氣時有最佳減阻效果7.2%。為了增加微泡覆蓋面 積，增設了球艏噴氣裝置，實驗結果發現球艏噴氣裝置與船底透 氣材共同噴氣有最佳減阻效果9.6%， 證明了增加微泡覆蓋面積 可增加減阻效果。

Energy saving and carbon reduction is one of the most important research in the world. With more than 80% of international trade in goods being carried by sea, reducing the resistance and raising the efficiency of ship propulsion is a great contribution to Energy saving and carbon reduction. The major target of the research is to develop the most promising and cleaning micro-bubble drag reduction technique in ship model. It is expected to develop a micro-bubble drag reduction technique which can be applied to the full scale ship. There are three micro-bubble generated methods used in this research. It includes pinhole, air/water mixer and porous plates. The pinhole method was not used in the drag reduction test because the air injected by pinhole is accumulated and form large bubble. The air/water mixer and aluminum porous plates were used to reduce the drag of flat-plate in towing tank. The drag reduction rate of aluminum porous plates was better than air/water mixer as shown from the test results. The 31.6% drag reduction was obtained by the micro-bubble generated by Aluminum porous plates when the model velocity is 3.6m/s. Thus the aluminum porous plates have been selected to apply on the ship model to verify the drag reduction effect. There are three aluminum porous plates have been installed on a flat bottom of ship model. The best drag reduction rate of 7.2% was found in this test. For better micro-bubble coverage, the bulb bow injector was set up on the ship model. The 9.6% drag reduction was obtained when both of bulb bow injector and aluminum porous plates operated at the same time. The test results prove that the better micro-bubble coverage bring the better drag reduction rate.