Good ventilation is critical for crew comfort, equipment heat dissipation, and air quality control in hazardous areas. Traditional ventilation design relies on empirical formulas and simple calculations, often only revealing issues such as air short-circuiting, dead zones, or local overheating after the vessel is in service, at which point correction is expensive. Jiangsu Haizhongzhou Shipping Industry Co., Ltd. has introduced computational fluid dynamics (CFD) simulation into the design phase of ventilation systems, followed by full-scale onboard testing to validate optimization results, forming a closed loop of “simulation–optimization–validation.”
During the CFD simulation modeling stage, engineers build 3D geometric models of engine rooms, cargo holds, or accommodation spaces based on the 3D design model, removing unnecessary fine details to control mesh count. They then define supply/exhaust locations and dimensions, duct routing, fan pressure and flow rate curves, and boundary conditions such as equipment heat output and wall temperatures. After tens of thousands of iterations, the solver outputs velocity fields, temperature fields, and pressure distribution contours. The design team evaluates issues such as air short-circuiting, low-velocity zones, dead zones, or local overheating, and then iteratively adjusts vent locations, deflector angles, or duct diameters until ideal performance is achieved.
Taking the engine room ventilation of an 85,000 DWT bulk carrier as an example, the original design showed airflow velocities of only 0.8 m/s around the main engine, with local temperatures reaching 48°C. Through CFD optimization, the discharge angles of two supply fans were adjusted, local supply branches were added above high-temperature equipment, and exhaust outlets were relocated from the top to the mid-upper portion of the engine room. The optimized design reduced the average engine room temperature from 42°C to 38.5°C, increased airflow velocity around the main engine to 1.5 m/s, and significantly improved temperature gradients near heat sources.
During the full-scale validation phase, engineers placed anemometers and temperature sensors at key locations, continuously recording data under various operating conditions and comparing them with CFD predictions. Results showed that airflow velocity deviations at key points were within ±8%, and temperature deviations were within ±1.2°C, confirming the reliability of the simulation model. CFD simulation has now become a standard step in Haizhongzhou Shipbuilding’s ventilation system design, and all newbuild vessels must pass simulation optimization before construction proceeds. This approach not only improves design quality but also reduces the cost and time of on-vessel rework, yielding significant comprehensive benefits.