Propulsion motors are vital components in marine propulsion systems and industrial machinery, where high torque and operational reliability are paramount. During operation, high-power propulsion motors generate considerable heat, which can adversely affect efficiency, durability, and stability. Therefore, an effective thermal management system is necessary to maintain optimal performance and ensure long-term reliability. Cooling technologies, such as water jackets, are commonly employed to regulate temperature distribution, prevent localized overheating, and preserve insulation integrity under high-power conditions. This paper examines the cooling performance of water jackets for high-power propulsion motors through numerical analysis. We evaluated the effects of three different cooling pipe locations and varying coolant flow rates on thermal balance and cooling efficiency. Additionally, we analyzed temperature variations in the windings and key heat-generating components to determine if a specific cooling flow rate and pipe configuration can effectively keep the winding insulation (Class H) within its 180^oC limit. The findings of this study highlight the significance of optimized cooling system design and contribute to the development of efficient thermal management technologies, ultimately enhancing motor reliability, operational stability, and energy efficiency.

This study presents a dual-impeller air-cooled heat exchanger aimed at improving thermal management in electro-optical tracking systems operating under high power density. Two geometric modifications were introduced to enhance flow characteristics and heat transfer performance: the curvature of the center plate and the integration of a pin-fin structure at the outlet. Through numerical simulation, the improved model demonstrated more efficient internal flow compared to the original model, achieved through enhanced inflow characteristics and reduced flow separation. The pin-fin structures induced localized turbulence and recirculation zones, contributing to an increased thermal exchange surface area and longer effective heat transfer time. Consequently, the outlet temperature of the internal system decreased by an average of 1.4°C across various rotational speeds, resulting in a 5.9% increase in heat exchanger efficiency compared to the original model. Overall, this study shows that structural enhancements in heat exchanger design can significantly improve the cooling performance of high-power electronic systems, suggesting practical applicability for advanced thermal management solutions.