عنوان مقاله [English]
Increase in speed and range of hydrodynamic systems, which ultimately lead to enhance in its performance, is one of the most important goals in design of marine systems. Achieving this goal, is required to reduce hydrodynamic drag. Micro-bubble injection technique is one of the active methods to reduce hydrodynamic drag. This approach has high efficiency for drag reduction and in comparison to the other active methods, it has less environmental pollution and it is easy to install on the hydrodynamic vehicles. The main aim of this research is experimental investigation of the hydrodynamic drag reduction of a catamaran vessel using micro-bubbles injection method and determining the effective parameters on the performance of this technique. For this purpose, at first, a catamaran vessel model is made with length of 70cm. In the following, the micro-bubble injectors are designed and installed with necessary equipment, for measurement of air flow rate, on three locations at fore, middle and aft sections of model. Experimental tests are carried out in towing tank laboratory for catamaran vessel with and without injection system for Froude numbers in the range of 0.44 to 1.48 and finally, the ability of micro-bubbles injection method to reduce hydrodynamic drag of catamaran vessel model is evaluated at different velocities. The experimental results revealed that, the average hydrodynamic drag reduction is attained about 17%. additionally, by increasing Froude number, the capability of miro-bubble injection method to reduce drag has been decreased from 21.15% to 11.8% for Fr=0.54 and Fr=1.25, respectively.
 Yunqing G, Tao L, Jiegang M, Zhengzan S, Peijian Z. Review Article Analysis of Drag Reduction Methods and Mechanisms of Turbulent. Applied Bionics and Biomechanics. 2017; Vol. 2017.
 جهانمیری محسن، بحرینی عبدالرسول. روشهای نوین کاهش نیروی درگ اجسام غوطهور در سیال. مجله مهندسی مکانیک. 1390; (81): 14-27.
 McCormic ME, Bhattacharyya R. Drag Reduction of Submersible Hull by Electrolysis. Naval engineering journal. 1973; 85: 11–16.
 Insel M, Gokcay S, Helvacioglu IH. Flow Analysis of an Air Injection through Discrete Air Lubrication. Paper Presented at: International Conference on Ship Drag Reduction; 2010;Istanbul, Turkey.
 Kazuyasu S, Kawamura T, Takagi S, Matsumoto Y. Numerical simulation on Drag Reduction Mechanism by Microbubbles. Ship performance division. National maritime Tokyo. 181-0004, Japan.
 Kato H, Yamaguchi H, Maeda M, Miyanaga M. Skin friction reducation by microbubbles Journal of Marine Science and Technology. 1996;5(1): 241–54.
 Hassan YA, Ortiz–villafuctte J. Experimental study of microbubble drag reduction using particle image velocimetry. Paper Presented at:11th international symposium on application of laser techniquies to fluid mechanics;2002 July8-11; Lisbon, Portugal.
 Mäkiharju SA, Perlin M, Ceccio SL. On the energy economics of air lubrication drag reduction. International Journal of Naval Architecture and Ocean Engineering. 2012 Dec 1;4(4):412-22.
 Jang J, Choi SH, Ahn SM, Kim B, Seo JS. Experimental investigation of frictional resistance reduction with air layer on the hull bottom of a ship. International Journal of Naval Architecture and Ocean Engineering. 2014 Jun 1;6(2):363-79.
 Zhang J, Yang S, Liu J. Numerical investigation of a novel device for bubble generation to reduce ship drag. International Journal of Naval Architecture and Ocean Engineering. 2018 Sep 1;10(5):629-43.
 Hao WU, Yongpeng O, Qing YE. Experimental study of air layer drag reduction on a flat plate and bottom hull of a ship with cavity. Ocean Engineering. 2019; 183: 236–48.
 Elghobashi S. On predicting particle-laden turbulent flows. Applied Scientific Research. 1994; 52(4): 309-22.
 Prasanta KS. CFD perdiction of the resistance of a catmarn with stagerd demi hulls. Paper Presented at: International Conference in Marine hydrodynamic; 18-23 Sep 2006; Egmond aan Zee, Netherlands.
 Cyro HJ. Tech Brief and Manual fabrication of Plexigalsses. Black Stone Industries Inc; 2005.