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Supercritical Carbon dioxide (sCO2) power cycles are rapidly developing and gaining popularity in waste heat recovery systems, as primary power cycles for a variety of heat sources such as nuclear, or as a stand-alone power cycle where fossil fuels are combusted. Akin to conventional gas turbines, sCO2-powered systems are pushing the boundaries for firing temperatures for higher efficiencies. Direct oxy-fired sCO2 systems will demand internal cooling of the airfoils for safe and reliable operations. Gas turbine cooling technology can be leveraged for that purpose. However, two key differences exist. First, the coolant medium is sCO2 instead of air, and second, sCO2 airfoils are much smaller compared to power-generation gas turbines. Novel AM manufacturing techniques promise advanced internal cooling geometries. This paper investigates a novel trailing edge cooling design to replace conventional pin fin arrays. Here, a lattice structure with microchannels is introduced. The study presents the changes in heat transfer due to the substitution of the heat transfer medium and the new geometry. The component is assumed to be printed Inconel 718. Based on an oxy-fired combustion sCO2 power cycle, coolant temperature and pressure and hot gas path temperature and pressure are chosen. The converging trailing edge duct is simulated in StarCCM+ using COOLPROP for sCO2 properties as a conjugate heat transfer model.

 

The University of Central Florida (UCF) trains future engineers and scientists for research-oriented careers through a number of programs and initiatives. One of the most recent is a Research Experiences for Undergraduates (REU) site based on next-generation transportation and energy housed within the Center for Advanced Turbomachinery and Energy Research (CATER) and the Department of Mechanical and Aerospace Engineering (MAE). The site unites eleven multi-disciplinary research projects around HYpersonic, Propulsive, Energetic, and Reusable Platforms (HYPER). A key goal of HYPER is to equip and motivate undergraduate students to pursue graduate school and/or a research-oriented career, particularly across a diverse student participant cohort. The site has held two cohorts, engaging 25 students in a ten-week intensive experience, conducting research under the guidance of faculty mentors and graduate students. Students explored career options through industry tours, professional development seminars, and mentor-led research seminars. This paper reports the program impacts on the students and discusses several lessons learned across the cohorts. 

The Rotating Detonation Engine has been seen as the next step for rocket propulsion applications with the advent of the Rotating Detonation Rocket Engine, an engine configuration developed by the Air Force Research Laboratory. In an effort to flight-test this engine and provide a dataset to train detonation-based simulation, the Rotating Detonation Rocket Engine has been tested in a collaborative effort including the University of Central Florida. For this testing, a thrust stand was developed to obtain the key thrust and impulse data necessary for advancing the engine to flight readiness. This thrust stand utilized the small-scale of the Rotating Detonation Rocket Engine to motivate an axial-loading measurement approach and the integration of an automatic-calibration subassembly, altogether which allows for incredibly accurate thrust measurements from an engine. Results using this thrust stand for two similar engine configurations are shown to validate the operation of the thrust stand. 

Training future engineers and scientists for the research-oriented careers necessary to deliver solutions to the challenges of hypersonic flight is important task for the aerospace community at-large. A number of programs and initiatives at the University of Central Florida (UCF) contribute to this need. Among them is the Research Experiences for Undergraduates (REU) site framed on HYpersonic, Propulsive, Energetic, and Reusable Platforms (HYPER) an program housed withing the Center for Advanced Turbomachinery Energy Research (CATER). This residential summer program convening on the UCF main campus prepares a group of undergraduate students to pursue doctoral-level degree programs in aerospace engineering and related disciplines. During the Summer 2021, the second term of the program, HYPER hosted fourteen students. Students conducted intensive research under the guidance of faculty mentors and their graduate student assistants. To support their complete development, HYPER students participated in industry tours, software training, technical seminars, and more. This paper reports the impact of the program in its second year. Data are derived from pre- and post-experience surveys, study groups, and technical assessment activities. Feedback from the first year were implemented in the second year. 

The attenuation of circumferential flow inherent in Rotating Detonation Rocket Engines (RDRE) through nozzle configurations is studied. The method used in this investigation consist of capturing highspeed side images of the exhaust to visualize the swirling flow. The images were processed through a dynamic mode decomposition code to resolve the main frequencies of the flow field at the exhaust. The obtained results were compared to the operational frequency of the engine computed with back-end images. Nozzle configurations were shown to have an influence on wave dynamics due to the induced back pressure. Results from the DMD method show similarity to those obtained from detonation surfaces. The nozzle configurations investigated are: 1) baseline without a nozzle, 2) aerospike nozzle only without the outer nozzle and 3) the inner and outer nozzles in conjunction.