Heat exchangers (HEXs) are essential in the thermal management of electrified aero engines are characterized by extensive heat transfer surfaces. In fuel-cell based electric propulsion systems, efficient heat rejection at low temperatures is crucial, presenting challenges such as high weight demands and significant drag, which can reduce overall aircraft efficiency. Accurately computing airflow through these complex structures is a major challenge. This study employs simplified modeling techniques to simulate airflow in cooling lines and HEX, with a focus on improving airflow characteristics to increase efficiency. The results demonstrate that increased curvature downstream correlates with reduced flow separation and improved flow stability, while excessive curvature upstream intensifies flow stagnation and separation, leading to increased pressure drops. Overall, this research provides critical insights that can support innovative designs of cooling lines and contributing to more efficient thermal management systems and improved performance in aerospace applications.