(5)On hydrodynamic analysis of stepped planing crafts

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Amin Najafi ^a,  Hashem Nowruzi ^b,*

^a Mechanical Engineering Department, Imam Hossein University, Tehran, Iran 

^b Department of Maritime Engineering, Amirkabir University of Technology (Tehran Polytechnic), Hafez Ave, No 424, P.O. Box 15875-4413, Tehran, Iran 

Received 15 March 2019; received in revised form 25 April 2019; accepted 26 April 2019 

Available online 1 May 2019 

Abstract

    Using transverse steps is one of the adopted strategies to improve the hydrodynamic characteristics of planing crafts. In the present paper, hydrodynamic characteristics of stepped planing crafts are numerically investigated. For this purpose, we analyzed the effects of five different types of transverse steps on lift to drag ratio, resistance, trim angle and sinkage of high speed planing crafts. Contours of pressure distribution on the bottom of crafts, water volume fraction and free-surface are also presented at different hull velocities. Computed numerical results are properly validated against our conducted towing tank experimental tests. 

© 2019 Shanghai Jiaotong University. Published by Elsevier B.V. 

This is an open access article under the CC BY-NC-ND license. (http://creativecommons.org/licenses/by-nc-nd/4.0/)  

Keywords: CFD; Stepped hull; Lift to drag ratio; Dynamic trim; Sinkage.