Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 64 for “"wing-body"”.
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Hybrid wing-body aircraft noise and performance assessment
Hybrid wing-body aircraft noise generation and boundary layer ingestion (BLI) performance trends with increased fan face Mach number inlet designs are investigated. The presented topics are in support of the NASA subsonic fixed wing project, which seeks to lower noise and increase performance by …
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Understanding Unsteady Corner Separation Within Wing-Body Junction Flows
<p>Wing-body junction flows, formed at the interface between a wing and fuselage surface, are a complex, coupled, three-dimensional, turbulent flow field. This thesis focused on the unsteady corner separation that develops at the trailing edge of this wing-body junction under certain conditions. A …
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Wall Features of Wing-Body Junctions: Towards Noise Reduction
… experiments have gone into studying idealized wing-body junction flows and their impact on horseshoe vortex and wake formation. The vortices have been found to generate regions of high surface pressure fluctuations and turbulence that are detrimental to structural components and acoustics. With …
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Design and acoustic shielding prediction of hybrid wing-body aircraft
… in aircraft design have focused on the growing concerns about the environment impact of aviation and the rising costs of fuel. Under NASA's N+2 subsonics fixed-wing project, hybrid-wing-body (HWB) aircraft are investigated with the goal to meet the N+2 noise, fuel burn, and emissions …
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Multi-fidelity analysis and reduced-order modeling of wing-body aerodynamics
Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2024-03-01 without embargo terms
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Multidisciplinary methods for performing trade studies on blended wing body aircraft
… with a focus on the conceptual design of Blended Wing Body (BWB) aircraft. The objectives of this thesis are twofold. The first objective is to create a multidisciplinary tool for the design of BWB aircraft and to demonstrate the performance of the tool on several example trade studies. The second …
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Nonlinear steady and unsteady aerodynamics of wings and wing-body-combinations
… unsteady incompressible flow over delta wings. Symmetric motions (pitching, heaving) and asymmetric motions (roll, yaw) are considered. Then the method is generalized to treat the nonlinear three-dimensional steady flow for bodies and wing body combinations. Numerical examples include …
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Control Power Optimization using Artificial Intelligence for Hybrid Wing Body Aircraft
… allocation optimization problem of Hybrid Wing Body (HWB) aircraft concepts for minimizing control power, hinge moments, and actuator forces, while keeping the system weights within acceptable limits. The main objective is to develop a proof-of-concept process suitable to demonstrate the …
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The effect of a fillet on a wing/body junction flow
Time-averaged properties of a wing-body-junction flow surrounding a cylindrical wing with a 1.5:1 elliptical nose and a NACA 0020 tail have been compared to those for the above wing with a 1.5 inch radius fillet normal to the wing's surface. An attempt was made to determine the effectiveness of the …
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Vibration control and gust alleviation of highly flexible blended-wing-body aircraft
… large deformations in the flexible, lightweight wings. These disturbances can potentially excite unstable modes within the flexible aircraft, depending on the flight speed and gust strength. In this thesis the open-loop and closed-loop dynamic responses of a blended-wing-body aircraft subjected …
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Guidance, navigation and control of a small, unmanned blended wing body aircraft
… consisted of both path planning and path following algorithms which allowed for the synthesis of general classes of paths useful to the application. With both the autopilot and guidance laws developed, the system could be tested under several atmospheric flight conditions. These took the form …
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An experimental study of a turbulent wing-body junction and wake flow
… in an incompressible turbulent flow around a wing-body junction. The measurements were performed adjacent to the body and up to 11.56 chord lengths downstream of the body. The junction wake flow entered an adverse pressure gradient region approximately 6 chord lengths downstream. This region's …
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The Multidisciplinary Design Optimization of a Distributed Propulsion Blended-Wing-Body Aircraft
… (MDO) of a distributed propulsion blended-wing-body (BWB) aircraft. The BWB is a hybrid shape resembling a flying wing, placing the payload in the inboard sections of the wing. The distributed propulsion concept involves replacing a small number of large engines with many smaller engines. …
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Engine design implications for a blended wing-body aircraft with boundary later ingestion
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2003.
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Skin friction measurements around a wing-body junction using oil- film laser interferometry
… to measure the skin friction around a wing-body junction in a three-dimensional, turbulent boundary layer with pressure gradients. The flow was dominated by the formation of a junction vortex generated at the nose of the wing-body. The oil-film skin friction results were compared with …
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Hydrogen powered hybrid wing body freighter systems analysis and conceptual design using the ACS tool
… a higher aircraft volume was needed. A Hybrid Wing Body was approximated in ACS because of the excess volume in that particular configuration. That made a HWB an attractive candidate for hydrogen fuel. The hydrogen candidate was scaled down to two additional sized to accomplish the function of …
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Control Power Optimization using Artificial Intelligence for Forward Swept Wing and Hybrid Wing Body Aircraft
Many futuristic aircraft such as the Hybrid Wing Body have numerous control surfaces that can result in large hinge moments, high actuation power demands, and large actuator forces/moments. Also, there is no unique relationship between control inputs and the aircraft response. Distinct sets of …
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Numerical Assessment of the Performance of Jet-Wing Distributed Propulsion on Blended-Wing-Body Aircraft
… the thrust across most, or all, of the wingspan of an aircraft. This can be accomplished by using several large engines and using a duct to spread out the exhaust flow to form a jet-wing or by using many small engines spaced along the span of the wing. Jet-wing distributed propulsion was …
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Observation and measurements of flow structures in the stagnation region of a wing-body junction
… in a water tunnel for two low speed cases. A wing consisting of a 3 : 2 elliptical nose and an NACA 0020 tail was used to simulate the junction vortex. A visual study using a hydrogen bubble technique was extensively conducted to investigate the flow structures in the stagnation region of the …
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Impact of Liquefied Natural Gas usage and payload size on Hybrid Wing Body aircraft fuel efficiency
This work assessed Hybrid Wing Body (HWB) aircraft in the context of Liquefied Natural Gas (LNG) fuel usage and payload/range scalability at three scales: H1 (B737), H2 (B787) and H3 (B777). The aircraft were optimized for reduced fuel burn and airframe noise at approach, based on NASA N+3 goals …
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