Numerical Thermal‐Hydraulic Evaluation of an Integrated Direct‐Indirect Oil Cooling System for an Electric Motor Under Steady‐State Overload Conditions

High‐power‐density electric motors require effective thermal management to ensure reliable operation of electric vehicle powertrains under overload conditions. This study numerically evaluates an integrated direct‐indirect oil cooling architecture for an electric motor using a steady‐state single‐phase CFD/CHT model. The direct path delivers ATF‐SP4 oil through nozzle passages to the winding and stator, while the indirect path circulates oil through housing channels. The SST k‐ω turbulence model and conjugate heat transfer analysis are used to examine oil flow redistribution, component temperatures, pressure drops, and performance evaluation criteria (PEC) under a 14.21 kW overload heat input. At a fixed total flow rate of 10 LPM, the 2.5/7.5 LPM direct/indirect flow ratio achieves the best thermal‐hydraulic balance, producing the highest average PEC of 1.153 among the tested ratios. Using this 25%/75% distribution, increasing the total flow rate to 40 LPM reduces the average winding, stator, and housing temperatures to 172.1°C, 152.5°C, and 65.6°C, respectively, and yields the highest PEC of 1.682. The results provide simulation‐based guidance for designing oil cooling strategies for high‐performance EV traction motors.