Wright-Patterson Air Force Base

About: Wright-Patterson Air Force Base is a other organization based out in Wright-Patterson AFB, Ohio, United States. It is known for research contribution in the topics: Laser & Microstructure. The organization has 5817 authors who have published 9157 publications receiving 292559 citations. The organization is also known as: Wright-Patterson AFB & FFO.

Active Flutter Suppression—A Flight Test Demonstration

Abstract: The first flight test demonstration of active flutter suppression has been successfully completed. The Control Configured Vehicles (CCV) B-52 test airplane was twice flown 10 knots faster than its flutter speed relying solely on an automatic control system for adequate damping. The design, safety considerations, mechanization, ground testing, and flight testing of the flutter mode control system are reported. Comparisons between flight test and theoretical results are presented. The system was tested at heavy and light airplane weights and tested for compatibility with simultaneous ride control, maneuver load control, fatigue reduction, and augmented stability.

Future of Flight Vehicle Structures (2000 to 2023)

Abstract: The journey in advancing flight is far from complete. Challenges to improve performance while reducing costs to acquire and operate air vehicles to fully exploit the potential benefits of flight for humankind remain formidable. Toward this goal, what progress can we anticipate in the next 20 years? The authors attempt to answer this question, sharing their collective vision for advancements in structures technology within the allotted timeframe. Their coverage spans experimental, general, military, and commercial aviation.

Composition determination of β-(AlxGa1−x)2O3layers coherently grown on (010) β-Ga2O3substrates by high-resolution X-ray diffraction

Abstract: We demonstrate X-ray-diffraction-based composition estimation of β-(Al x Ga1− x )2O3 coherently grown on (010) β-Ga2O3. The relation between the strain along the [010] direction and the Al composition of the β-(Al x Ga1− x )2O3 layer was formulated using the stress–strain relationship in the monoclinic system. This formulation allows us to estimate the Al composition using the out-of-plane lattice spacing determined by conventional X-ray ω–2θ measurements. This method was applied to molecular-beam-epitaxy-grown coherent β-(Al x Ga1− x )2O3/Ga2O3 heterostructures, and the Al composition in β-(Al x Ga1− x )2O3 agrees closely with the composition determined directly by atom probe tomography.

Development of methods for the quantification of microstructural features in α + β-processed α/β titanium alloys

Abstract: A set of stereological procedures has been developed for the rigorous quantification of microstructural features resolvable using scanning electron microscopy in α + β-processed α/β titanium alloys. This paper identifies the four microstructural features that most likely influence the mechanical properties in α + β-processed titanium alloy, including: the size of the equiaxed alpha, the volume fraction of the equiaxed alpha, the volume fraction of total alpha, and the thickness of the Widmanstatten alpha laths. The details regarding the quantification methodologies are provided, as are the origins of the associated uncertainties.

Vibration-Dissociation Coupling Using Master Equations in Nonequilibrium Hypersonic Blunt-Body Flow

Abstract: Numerical simulations are presented of a steady-state hypersonic flow past a hemisphere cylinder. Two types of models, one a lumped Landau-Teller vibrational relaxation model (Landau, L., and Teller, E.) and the other a discrete state kinetic relaxation model (DSKR), were used to study effects of vibration-dissociation coupling on the flow physics. The widely used Park's dissociation model was used as baseline for coupling vibration and dissociation processes (Park, C.). For a Mach 8.6 flow, both relaxation models matched experimental data. At Mach 11.18, however, the underprediction of shock-standoff distance by both relaxation models using Park's model for dissociation coupling provided the motivation to implement a new master equation-based (DSKR) depletion model. The new model was used to study the effect of dissociation on population depletion in the vibrational states of the nitrogen molecule. The new model helps explain the restricted success of Park's dissociation model in certain temperature ranges of hypersonic flow past a blunt body. In the range of 5000-15,000 K, the new model yielded a substantial rate reduction relative to Park's equilibrium rate at lower temperatures and a consistent value at the high end