Movimentos de uma embarcação do tipo expresso em ondas regulares incidindo pela proa

Abstract

Navigation on the Amazon rivers can usually be carried out in calm waters. However, there is evidence recorded by the regional media and by some studies that it is also subject to interaction with waves, which tend to be generated during adverse environmental conditions. The frequency of encountering these waves can be significant for some vessels that navigate in the region, influencing their movement. This work proposes a study of the behavior in waves of a longitudinal transport expresso-type passenger vessel. An analysis of the heave and pitch movements is proposed under conditions of head regular waves, using the tools available in the Ansys Aqwa software. A free floating and forward speed conditions of 3 and 12 m/s were evaluated, under the constraints of the potential flow theory of hydrodynamics. The first stage of the study was carried out in the Hydrodynamic Diffraction module, analyzing the movements in regular waves between 1 and 20 seconds of period, among which the waves that cause the largest displacements were found. Subsequently, considering the regular wave that caused the largest pitch displacement (~5-second period), the vessel movements were simulated in the Hydrodynamic Response module, evaluating the effect of wave amplitude variation (0.25, 0.50, 0.75, and 1.00 m) on the movements. The results suggest that waves of length close to the vessel length can cause the largest heave and pitch displacements. In the simulations performed in Hydrodynamic Response, some possibilities of dangerous interactions with the waves were identified, including slamming and water shipping on the deck. Shipping water in the evaluated condition can occur when the wave amplitude exceeds approximately 0.75 m. The study can be extended to other regional vessels, being still necessary to validate the software results with experimental data, including specific measurements of the waves in the region.