SEMINAR: Design and Optimization of Systems in the Time Domain
Rory A. Roberts
Associate Professor, Department of Mechanical and Materials Engineering - Wright State University
Dr. Rory Roberts obtained his PhD in Mechanical Engineering at the University of California-Irvine. At UCI, Rory developed models for high temperature fuel cell/ gas turbine hybrid systems. He worked 4 years at Rolls-Royce Fuel Cell Systems in fuel cell gas turbine hybrid system design, development and testing. Rory joined Wright State University in 2009 and is currently an Associate Professor of Mechanical Engineering at Wright State University. Rory founded the Advanced Propulsion, Power and Thermal Systems program at Wright State University 2012. His research has generated over $1M in funding in the past 3 years. His current areas of research are in: transient model development for propulsion, power and thermal systems for system design, optimization and control architecture development. Some examples are: tip-to-tail vehicle modeling of aircraft and unmanned aircraft, fuel cell systems, high energy lasers, and power and thermal management systems.
System integration and design is traditionally a steady-state driven process during the conceptual design stage. Steady-state conceptual design optimization provides single point realization although sometimes off-design points are considered for compliance of operation within the design constraints. As this approach provides a method for designing a system under steady-state operating points, it does not provide insight in how the system will transition from one operating point to another. Also, the path dependent behavior is completely ignored. As complex highly integrated systems emerge, the need for path dependent transient behavior becomes increasingly important as systems become more synergetic with increased performance providing very little margin for uncertainty in the design. To reduce the uncertainty in the design, the transient behavior is needed during the conceptual design process to ensure desired operation and behavior of the system is achieved. Transient analysis requires development and inclusion of controls, which are specific to a particular system both in architecture and component sizing. Therefore a control system has to be included for every conceptual system and redesigned for every design iteration during the design optimization process. Control systems are subjective and can mislead the design process by hindering the system’s performance if not developed correctly. Therefore during the conceptual design process the control system must be automatically developed or eliminated as part of the process. A methodology of performing transient design optimization of a system is in development with the objective of defining the overall design process of a complex integrated system including conceptual, preliminary and detailed design with a control system. The methodology will co-design the system and the control system during the process for desired performance and behavior. A tool for rapid analysis of a transient system will be the presented as well as current applications in aerospace vehicles and systems, fuel cell power units, and power and thermal management systems.