Heat exchangers facilitate thermal energy transfer between media, either separated by solid boundaries or in direct contact. These devices are essential across numerous industries including refrigeration, power generation, chemical processing, petroleum refinement, and wastewater management. A common application exists in combustion engines where coolant circulates through radiator coils as air passes, cooling the fluid while heating incoming air. This study investigates heat transfer characteristics using carbon-water nanofluids compared to conventional water. The research combines experimental measurements with computational fluid dynamics simulations in Ansys Fluent, with model geometry created through GAMBIT pre-processing. The analysis examines nanoparticle concentration effects on thermal efficiency and pressure drop characteristics across different exchanger configurations. Advanced turbulence models help analyze the relationship between nanofluid properties and heat exchanger performance. Results demonstrate that carbon-water nanofluids offer significant improvements in thermal conductivity compared to standard coolants. The computational predictions align with experimental findings, validating the simulation approach. This integrated methodology provides valuable insights for optimizing thermal management systems from engine cooling to industrial applications, addressing limitations of traditional heat transfer fluids through practical, numerically-verified solutions.