effect of deadrise angle on wet surface and hydrodynamic parameters of planning vessel by experimental and numerical methods

Abstract: today, with the expansion of maritime trade and the need to use high speed in vessels, the analysis of this type of vessel is of particular importance. in this research, using numerical and experimental methods, the effect of deadrise angle of vessel on hydrodynamic parameters is investigated. the experimental method has been used as an accurate and tested method for estimating hydrodynamic parameters. but in the case of planing vessels, determining the wet surface of the vessel is not easy. for this purpose, numerical method has been used to determine the wet surface of the planing vessel in this research. first, the experimental results of the current research are compared with the laboratory results of david taylor, and then, the numerical results are validated with the experimental results. by validating the numerical and experimental results, the floating wet surface is calculated and finally the hydrodynamic dimensionless coefficients are calculated for each deadrise angle. comparison of laboratory results of the present study with the laboratory results of david taylor shows the recording of very good results in the laboratory. also, the comparison of numerical and experimental results in this study, which is less than 10%, shows the high accuracy of numerical results. finally, by comparing the percentage of wet surface increase in the two deadrise angles, it is concluded that at the speed of 5.71, there is a nearly 20% increase in the wet surface at the deadrise angle of 25 compared to the deadrise angle of 20°. also, by comparing the coefficients of total resistance, at the speed of 5.71 m/s, the coefficient of total resistance of the boat with deadrise angle 20o, is %15 more than 25°.

Experimental and numerical study on the effect of deadrise angle on hydrodynamic parameters of prismatic planing models

In this research, by using Experimental and numerical methods, the hydrodynamic parameters of highspeed prismatic vessel including resistance, rise up and trim for two deadrise angles of 20 and 25 have been investigated. In this paper, first, the experimental results with 2 deadrise angles 20 and 25 with David Taylor Towing Tank results are compared and the hydrodynamic parameters including resistance, rise up and trim are investigated. Then, by modeling the vessel by finite volume method and computational fluid dynamics, the hydrodynamic parameters have been validated and compared and the wet surface of the vessel has been computed at two deadrise angles in different forward speeds. In this study, it was found that the amount of floating resistance increases with increasing deadrise angle. Also, the dynamic trim decreases with increasing deadrise angles at different forward speeds.