Aerodynamic Optimization of Mass Rapid Transit (MRT) Cabin Design for Enhanced Energy Efficiency
Urban congestion and rising energy demand represent critical challenges for sustainable transportation development in rapidly growing metropolitan areas such as Jakarta. As a low-carbon public transport alternative, the Mass Rapid Transit (MRT) system plays an essential role in enhancing urban mobility while mitigating greenhouse gas emissions. Improving the aerodynamic performance of MRT trains is therefore crucial to reducing operational energy consumption. This study examines the aerodynamic optimization of the MRT cabin geometry by redesigning the front nose configuration. A right-triangle cabin profile is proposed to replace the conventional blunt geometry derived from the Ahmed body model. Three-dimensional modeling was conducted in SolidWorks, followed by Computational Fluid Dynamics (CFD) simulations in ANSYS Workbench using the k–ε and k–ω SST turbulence models. Simulations were performed at speeds of 80, 100, and 120 km/h to assess key aerodynamic parameters, including drag coefficient (Cd), pressure contour distribution, velocity streamlines, and vortex formation characteristics. The results reveal that the proposed triangular configuration reduces aerodynamic drag, achieving a Cd value of 0.0629 at 120 km/h compared to 0.59575 for the reference model. Furthermore, the redesigned cabin produces smoother pressure gradients and reduced wake vortex intensity, indicating improved airflow stability. These aerodynamic improvements translate into lower traction power requirements within the 65 MW operational limit. Overall, the findings demonstrate that geometric refinement of MRT cabin design can enhance energy efficiency without increasing operational costs, thereby supporting sustainable urban transport systems and national green economy objectives. These findings provide insights for future MRT aerodynamic optimization.