Investigation of the towing resistance of a catamaran with simplified hull forms

The use of catamarans can be an effective solution for organizing mass passenger transportation on waterways. At the same time, there is a need to improve shipbuilding technology. The use of simplified hulls can be successfully employed to optimize the production process and significantly reduce construction costs. This article provides an analysis of existing studies on the resistance of vessels with simplified hull forms. It is shown that, in most cases, simplification of the hull form leads to an increase in towing resistance of up to 30%. The article presents the results of a model experiment conducted in the towing tank of the Admiral Makarov State University of Maritime and Inland Shipping. The model, with a single hull length of 2000 mm and a beam of 148 mm, was tested in calm water at three different drafts (60 mm, 80 mm, and 100 mm) and at speeds ranging from 1 m/s to 4 m/s, corresponding to Froude numbers between 0.22 and 0.90. The paper plots the towing resistance curves for the catamaran with simplified hull forms and presents the results of an experimental study of the effect of trim and draft on the towing resistance. The dependences of the residual resistance coefficient on the Froude number are examined. The data obtained during the experiment are compared with published results of propulsive performance studies of catamarans with similar principal particulars. The study provides evidence that simplifying the hull forms of high-speed multi-hull vessels negatively impacts towing resistance. It is concluded that the results obtained can be used in the design of vessels with simplified hull forms.