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Abstract 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. 

Lightweight structures with bioinspired metamaterials, with their uniquely engineered properties not found in naturally occurring materials, have garnered significant attention for their potential in various engineering applications. This study explores the mechanical behavior of sandwich plate structures utilizing the Kresling origami pattern, fabricated through a straightforward 3D printing process. By conducting 3-point bending and compression tests, as well as simulations with Abaqus software, the research investigates the distinctive mechanical properties and performance enhancements these origami-inspired structures offer under mechanical loading. This study is noteworthy for being the first to investigate the bending characteristics of sandwich structures utilizing the two cell Kresling pattern or double Kresling, an area that has not been previously explored. Utilizing the Kresling structure in sandwich panels poses a challenge due to its rotational behavior. To address this, we employ a double Kresling pattern, which confines the rotation to the middle layer. This approach ensures that the outer layers remain stable, maintaining the overall integrity of the sandwich panel structure during deformation under mechanical loading. The findings reveal that the 3D-printed Kresling origami core significantly reduces weight while maintaining structural integrity, making it especially beneficial for aerospace engineering, where lightweight yet strong materials are crucial. This research highlights the potential of Kresling-patterned sandwich plates to improve efficiency and performance in supersonic vehicles, providing valuable insights into their structural efficiency and applicability in advanced engineering fields. 

Progress towards future modes of transportation and energy production has uncovered significant knowledge gaps impeding technical progress. Realizing aircraft that regularly operate in supersonic and even hypersonic regimes and turbomachinery supporting carbon neutrality can be addressed only through multi-disciplinary research. The University of Central Florida (UCF) equips future engineers and scientists for research-oriented careers through a variety of programs and initiatives. One key initiative is a Research Experiences for Undergraduates Site housed within the Center for Advanced Turbomachinery and Energy Research and the Department of Mechanical and Aerospace Engineering. Now hosting its fifth cohort, the site unites multi-disciplinary projects around HYpersonic, Propulsive, Energetic, and Reusable Platforms (HYPER). Beyond graduate-level research with expert faculty, participants engage in a professional development series, industry tours, and computational software training. UCF plays a key role in preparing a workforce of young scientists for research careers in hypersonics. This paper presents data drawn from the four completed cohorts of HYPER participants on how exposing participants to the various disciplines has impacted their self-efficacy, as well as a brief summary of lessons learned along the way. With this site, UCF plays a key role in preparing a workforce of young scientists for research careers in hypersonics. 

Design considerations for a new detonation tube are presented to further improve detonation wave interaction research. The new structure consists of four independent portions: the deflagration to detonation initiation section, the transition expansion section, the operating test section, and the dump section. The initiation, transition, and test sections are designed to operate within a temperature limit of 150 °C and a maximum detonation pressure of 100 bar. The test section is comprised of interchangeable 155 cm 316 stainless steel plates assembled to create a 10x10 cm square hollow structure, sealed with longitudinal O-rings between plates and lateral O-rings between flanges and plate ends. The ports and windows are all sealed with O-rings. The current assembly has 30 circular ports for pressure measurements and ion gauge measurements. These same circular ports will also be used for laser spectroscopy measurements through 1.27 cm diameter circular windows. Two axial rectangular windows of 16.51 x 5.74 cm and two of 16.51 x 2.54 cm, with centers 52 cm from the downstream end of the test section, are used for various diagnostics and imaging techniques. Hydrostatic droplet release, piezo-actuated droplet release, and vibration-induced droplet release have been designed and discussed. 

The deformation and breakup of water droplets impacted by a shock wave has been largely attributed to surface mechanisms. This study investigates the possibility of cavitation-induced droplet breakup. Shock waves of Mach 4 are used in this study to impact groups of droplets, both groups of degassed droplets and a group of non-degassed droplets. Distilled water droplets on the order of 1-3 mm in diameter are introduced into the shock tube. High speed images and deformation plots are used to explore the existence of cavitation in the droplets, as well as how they deform comparatively. 

Aluminum powder has been commonly used as the energetic material in solid propellants due to its high energy density. However, in actual combustion scenarios, not all aluminum powder is able to completely burn before reaching the nozzle, owing to the complicated physics of aluminum combustion. Due to this complexity, many studies have relied on analytic solutions instead of directly solving the Navier-Stokes equations. These earlier studies exhibit limitations, such as the inability to explain mass and heat transfer occurring at the interface or simulate 3-D fluid dynamics. In this study, the Volume of Fluid (VOF) method was employed to conduct direct numerical simulations of aluminum droplet evaporation. Subsequently, the developed model was compared and assessed against the evaporation model provided by the Lagrangian solver.