Schwentker, Robert AndrewHeat exchangers play an important role in a variety of energy conversion applications. They have a significant impact on the energy efficiency, cost, size, and weight of energy conversion systems. CoilDesigner is a software program introduced by Jiang (2003) for simulating and optimizing heat exchangers. This thesis details advances that have been made to CoilDesigner to increase its accuracy, flexibility, and usability. CoilDesigner now has the capability of modeling wire-and-tube condensers under both natural and forced convection conditions on the air side. A model for flat tube heat exchangers of the type used in automotive applications has also been developed. Void fraction models have been included to aid in the calculation of charge. In addition, the ability to model oil retention and oil's effects on fluid flow and heat transfer has been included. CoilDesigner predictions have been validated with experimental data and heat exchanger optimization studies have been performed.en-USThesisEngineering, MechanicalHeat ExchangerSimulationOptimizationVoid fractionWire-and-Tube CondenserHeat Transfer Coefficient