| A passenger Ro-Ro ship is a type of vessel commonly used for transporting people and vehicles.The ventilation system in the vehicle compartment provides a comfortable,safe,and healthy environment by introducing fresh air,exhaust gases,controlling temperature,and preventing fires.The vehicle compartment ventilation system is one of the important aspects to ensure the safety of the ship and the comfort of the passengers.Reasonable simulation analysis and optimization design of the ventilation system of the vehicle compartment of the Ro-Ro ship are of great significance for ensuring the air quality inside the compartment and the health and safety of the passengers.(1)To address the issues of uneven internal flow field distribution,poor ventilation effectiveness,and high pollutant concentration in the vehicle compartment of Ro Pax vessels,research was conducted on the distribution of air flow field in the compartment.The ventilation situation of the vehicle compartment under loading and sailing conditions was simulated and analyzed.The velocity field,pressure field distribution,and uniformity of the flow field distribution inside the compartment,as well as above the vehicle cross-section and above the vehicle,were obtained.Further analysis was conducted on the distribution of the flow field under different ventilation modes,and the uniformity of the flow field distribution under different ventilation modes was determined.Research on the diffusion of pollutants inside the compartment was conducted.By transient simulation and analysis of CO release and diffusion process from a fixed point in the vehicle compartment,the diffusion of CO inside the compartment and the change of CO mass fraction inside the compartment within 0-200 seconds were dynamically analyzed.(2)To improve the ventilation performance of the wind ducts in the vehicle compartment and address the issues of poor ventilation effectiveness and significant energy loss,structural optimization research was conducted on the wind ducts in the vehicle compartment.The influence of single factors such as wind duct inlet size,wind duct outlet size,inlet inclination angle,wind duct length,and deck openings on the ventilation performance of the wind duct was studied.The influence laws and degrees of each factor on the ventilation performance of the wind duct were obtained.Based on the orthogonal experimental design,a size optimization study of the wind duct structure was conducted,and the wind duct structure parameters under the minimum wind duct resistance and pressure drop were obtained.Based on relevant ventilation design standards,the optimization of turning angles and guide vanes of the wind duct was conducted,which improved the ventilation performance of the wind duct.(3)To address the difficulties in evaluating the ventilation effectiveness of the wind duct,research was conducted on the prediction and validation of pressure drop of variable cross-section wind ducts to achieve rapid evaluation of wind duct design.A parameterized wind duct model was established,and parameterized simulation analysis was conducted to obtain the input-output parameter table,which was divided into training set data and test set data.A wind duct pressure drop prediction model was established,and model training and testing were conducted based on simulation data to achieve rapid evaluation of wind duct energy loss based on wind duct pressure drop.A wind speed measurement platform was set up,and wind speed measurement was conducted.The predicted pressure drop was compared with the measured pressure drop to verify the accuracy of the predicted results. |
