Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)


Aerospace, Physics, and Space Sciences

First Advisor

Daniel R. Kirk

Second Advisor

Héctor M. Gutiérrez

Third Advisor

Chelakara Subramanian

Fourth Advisor

Charles T. Fulton


A thermal cycle is a device that converts thermal energy into work energy. There is a strong need in the United States and the world for a cycle that can have viable performances with low-grade temperature heat sources to increase the supply of power generation. There are many cycles with different configurations, however most do not involve mixing. Generally speaking this is due to modeling difficulties with multiple constituents, phases, and the technology available that lose performance under these mixed conditions. The gap in technology for mixed flow and phase components is getting smaller due to the need. Current cycles may look great in a modeling environment, but begin to suffer due to their complexity and losses in components. Harris Corporation and Florida Institute of Technology have worked together in improving cycle performance with low-grade temperature heat source by combining three traditional cycles: Rankine, Brayton, and Refrigeration into a cycle called Imbedded Organic Rankine Cycle (IOC). The main purpose of this design is to move energy strategically in order to improve the conversion of heat energy into work energy. The majority of waste heat available in the U.S. is considered low-grade which is below 450ºF. Cycle performance goes down with lower temperatures which provides a challenge to engineers. Florida Institute of Technology was tasked to develop multiphase, multi-constituent models for cycle analysis and validation of Harris Corporation thermodynamic models. This was achieved by starting out with direct thermo-fluid lookup via National Institute of Standards and Technology data then to simple models and then gradually building up to more complex cycle component models. This dissertation details the derivations, applications, and comparison of cycles and their components. A detailed set of numerical results is presented and suggestions for future work are discussed.


Copyright held by author.