Experimental analysis of the hydrodynamic resistance of a scale-model barge during free deceleration

Abstract

Hydrodynamic resistance influences the deceleration of inland vessels and navigation safety. This study determined the resistance coefficients of a 1:50 scale-model barge and compared linear, quadratic, and combined resistance models during free deceleration. In towing tank experiments, the model was towed and released, with its motion recorded using a high-speed camera and trajectories extracted using Tracker software. The parameters were estimated through nonlinear least-squares fitting, considering a theoretical estimate of longitudinal added mass, and evaluated using RMSE, R², AIC, BIC, and the Durbin–Watson statistic. In nine tests with the unloaded barge, all models achieved R² values exceeding 0.999. Among eight distinct datasets, the linear model yielded lower errors in six, while the quadratic model performed better in two; the combined model improved selected fits. However, coefficient variability and residual autocorrelation revealed limitations in the formulations, indicating the need for further investigation of hydrodynamic resistance mechanisms to adequately represent the vessel's dynamics.