Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- EVTOL (4)
- Additive manufacturing (3)
- CFD (3)
- LES (3)
- VPM (3)
-
- Vortex particle method (3)
- Aerodynamics (2)
- Electric aircraft (2)
- Hybrid manufacturing (2)
- Large-eddy simulation (2)
- MDO (2)
- Multirotor (2)
- Rotors (2)
- UAM (2)
- Urban air mobility (2)
- VTOL (2)
- 316 SS (1)
- 316 stainless steel (1)
- AWE (1)
- Actuator surface (1)
- Adhesion (1)
- Adjoint (1)
- Aeroelastic optimization (1)
- Aeroelasticity (1)
- Aerostructural (1)
- Airborne wind (1)
- Aircraft (1)
- Augmentation (1)
- Balling (1)
- Blade design (1)
Articles 1 - 16 of 16
Full-Text Articles in Engineering
Retention Forces For Drops On Microstructured Superhydrophobic Surfaces, Shaur Humayun, R. Daniel Maynes, Julie Crockett, Brian D. Iverson
Retention Forces For Drops On Microstructured Superhydrophobic Surfaces, Shaur Humayun, R. Daniel Maynes, Julie Crockett, Brian D. Iverson
Faculty Publications
Accurate models of retention forces between drops and superhydrophobic (SH) surfaces are required to predict drop dynamics on the surface. This retention force is, in turn, useful in modeling heat transfer rates for dropwise condensation on a SH surface. Drop contact angle distribution and base area on SH surfaces are essential factors for predicting retention forces. The present work measures the contact angle distribution and base area shapes of various drop sizes over a wide range of solid fraction for inclined microstructured SH surfaces at the point of drop departure. Base area shape was found to be well approximated using …
Meshless Large Eddy Simulation Of Propeller-Wing Interactions With Reformulated Vortex Particle Method, Eduardo Alvarez, Andrew Ning
Meshless Large Eddy Simulation Of Propeller-Wing Interactions With Reformulated Vortex Particle Method, Eduardo Alvarez, Andrew Ning
Faculty Publications
The vortex particle method (VPM) has gained popularity in recent years due to a growing need to predict complex aerodynamic interactions during preliminary design of electric multirotor aircraft. However, VPM is known to be numerically unstable when vortical structures break down close to the turbulent regime. In recent work, the VPM has been reformulated as a large eddy simulation (LES) in a scheme that is both meshless and numerically stable, without increasing its computational cost. In this study, we build upon this meshless LES scheme to create a solver for interactional aerodynamics. Rotor blades are introduced through an actuator line …
Reliability Study Of A New Electromechanical Device Designed To Measure The Relative Dorsal Mobility Of The First Ray Of The Foot, Philippe Passeraub
Reliability Study Of A New Electromechanical Device Designed To Measure The Relative Dorsal Mobility Of The First Ray Of The Foot, Philippe Passeraub
Faculty Publications
Introduction: A new electromechanical instrument has been developed to measure relative dorsal mobility of the first ray in an objective and reliable way by simulating ground reaction forces during gait. This device equally applies a standardized, electronically controlled, and precise force under the first metatarsal head M1 as well as under the heads of the lesser metatarsals M2 to M5. The relative dorsal mobility between these two bearings is then measured. The purpose of this study is to assess the intra- and inter-examiners reliabilities of the measurements obtained with this device. Methods: The protocol included two examiners and 36 feet …
Reliable Mode Tracking For Gradient-Based Optimization With Dynamic Stability Constraints, Taylor Mcdonnell, Andrew Ning
Reliable Mode Tracking For Gradient-Based Optimization With Dynamic Stability Constraints, Taylor Mcdonnell, Andrew Ning
Faculty Publications
In order to construct mode-specific flutter constraints for use in gradient-based multidisciplinary design optimization frameworks, mode tracking must be used to associate the current iteration's modes with the modes corresponding to each constraint function. Existing mode tracking methods, however, do not provide a method by which to ensure the accuracy of mode associations, making them unsuitable for use in situations where obtaining correct mode associations is critical. To remedy this issue, a new mode tracking method is presented which incorporates backtracking logic in order to maintain an arbitrarily high degree of confidence in mode correlations during gradient-based optimization and/or during …
Impact Of Zirconia Slurry In Steel Powder On Melt Pool Characteristics In Laser Powder Bed Fusion, Taylor Davis, Tracy W. Nelson, Nathan B. Crane
Impact Of Zirconia Slurry In Steel Powder On Melt Pool Characteristics In Laser Powder Bed Fusion, Taylor Davis, Tracy W. Nelson, Nathan B. Crane
Faculty Publications
Purpose – dding dopants to a powder bed could be a cost-effective method for spatially varying the material properties in laser powder bed fusion (LPBF) or for evaluating new materials and processing relationships. However, these additions may impact the selection of processing parameters. Furthermore, these impacts may be different when depositing nanoparticles into the powder bed than when the same composition is incorporated into the powder particles as by ball milling of powders or mixing similarly sized powders. This study aims to measure the changes in the single bead characteristics with laser power, laser scan speed, laser spot size and …
Effects Of Rotor-Airframe Interaction On The Aeromechanics And Wake Of A Quadcopter In Forward Flight, Denis-Gabriel Caprace, Andrew Ning, Philippe Chatelain, Grégoire Winckelmans
Effects Of Rotor-Airframe Interaction On The Aeromechanics And Wake Of A Quadcopter In Forward Flight, Denis-Gabriel Caprace, Andrew Ning, Philippe Chatelain, Grégoire Winckelmans
Faculty Publications
From small drones to large Urban Air Mobility vehicles, the market of vertical take-off and landing (VTOL) aircraft is currently booming. Modern VTOL designs feature a variety of configurations involving rotors, lifting surfaces and bluff bodies. The resulting aerodynamics are highly impacted by the interactions between those components and their wakes. This has consequences on the aircraft performance and on the downstream wake. Studying the effects of those interactions through CFD can inform the development of cheaper numerical models. In this work, we focus on the interaction between rotors and bluff bodies based on the example of a generic quadcopter …
Trade-Off Characterization Between Social And Environmental Impacts Using Agent-Based Models And Life-Cycle Assessment, Joseph C. Leichty, Christopher S. Mabey, Christopher A. Mattson, John L. Salmon, Jason Weaver
Trade-Off Characterization Between Social And Environmental Impacts Using Agent-Based Models And Life-Cycle Assessment, Joseph C. Leichty, Christopher S. Mabey, Christopher A. Mattson, John L. Salmon, Jason Weaver
Faculty Publications
Meeting the UN’s sustainable development goals requires designers and engineers to solve multi-objective optimization problems involving trade-offs between social, environmental, and economic impacts. This paper presents an approach for designers and engineers to quantify the social and environmental impacts of a product at a population-level and then perform a trade-off analysis between those impacts. In the approach, designers and engineers define the attributes of the product as well as the materials and processes used in the product’s life cycle. Agent-Based Modeling (ABM) tools that have been developed to model the social impacts of products are combined with Life- Cycle Assessment …
Optimizing Build Plate Adhesion Of Polymers In Fused Granule Fabrication Processes, Alex Schroeder, Jason Weaver
Optimizing Build Plate Adhesion Of Polymers In Fused Granule Fabrication Processes, Alex Schroeder, Jason Weaver
Faculty Publications
Perhaps the most crucial element of fused granule fabrication (FGF) is material adhesion; in order to achieve a successful product, the material being printed must adhere to the build plate. For optimal products, the material should only adhere to the build plate until the print is complete, then be easily removable. This paper examines the effects of different build plates, environments, and bonding agents on material adhesion during the FGF process in a CNC mill machine. The force to remove polycarbonate (PC) and polypropylene (PP) from build plates was tested with various bonding agents. Except in one case, the adhesive …
A Comparison Of Layer Deposition And Open Molding Of Petg By Fused Pellet Fabrication In An Additive Manufacturing System, Alex Gibson, Jason Weaver
A Comparison Of Layer Deposition And Open Molding Of Petg By Fused Pellet Fabrication In An Additive Manufacturing System, Alex Gibson, Jason Weaver
Faculty Publications
Additive manufacturing continues to offer new possibilities in both production and economics. The industry has quickly adopted it to rapidly produce parts that would be difficult or cost preventative otherwise. Recent innovation has expanded its capabilities, however there are still significant limitations. Most AM processes are restricted by materials available, in producing large parts, or by not achieving material deposition speeds to make certain products feasible. In addition, tight tolerances for features and surfaces cannot be produced without substantial post processing. High-speed Fused Pellet Fabrication (FPF) in combination with Hybrid Manufacturing (HM) offers expanded capabilities as additive and subtractive process …
Optimization Of Solar-Coal Hybridization For Low Solar Augmentation, Aaron T. Bame, Joseph Furner, Ian Hoag, Kasra Mohammadi, Kody Powell, Brian D. Iverson
Optimization Of Solar-Coal Hybridization For Low Solar Augmentation, Aaron T. Bame, Joseph Furner, Ian Hoag, Kasra Mohammadi, Kody Powell, Brian D. Iverson
Faculty Publications
This work presents a process to determine the preliminary optimal configuration of a concentrating solar power-coal hybrid power plant with low solar augmentation, and is demonstrated on a regenerative steam Rankine cycle coal power plant in Castle Dale, UT, USA (average DNI of 542 W m−2). A representative plant model is developed and validated against published data for a coal power plant. The simplifications that lead to the representative model from a coal power plant model include combining multiple feedwater heaters, combining turbines, and using a mass-average calculation for extraction steam properties. Comparing net power generation and boiler …
Flowunsteady: An Interactional Aerodynamics Solver For Multirotor Aircraft And Wind Energy, Eduardo Alvarez, Judd Mehr, Andrew Ning
Flowunsteady: An Interactional Aerodynamics Solver For Multirotor Aircraft And Wind Energy, Eduardo Alvarez, Judd Mehr, Andrew Ning
Faculty Publications
The ability to accurately and rapidly assess unsteady interactional aerodynamics is a shortcoming and bottleneck in the design of various next-generation aerospace systems: from electric vertical takeoff and landing (eVTOL) aircraft to airborne wind energy (AWE) and wind farms. In this study, we present a meshless CFD framework based on the reformulated vortex particle method (rVPM) for the analysis of complex interactional aerodynamics. The rVPM is a large eddy simulation (LES) solving the Navier-Stokes equations in their vorticity form. It uses a meshless Lagrangian scheme, which not only avoids the hurdles of mesh generation, but it also conserves the vortical …
Large Eddy Simulation Of The Wakes Of Three Urban Air Mobility Vehicles, Denis-Gabriel Caprace, Andrew Ning
Large Eddy Simulation Of The Wakes Of Three Urban Air Mobility Vehicles, Denis-Gabriel Caprace, Andrew Ning
Faculty Publications
Recent advances in urban air mobility have driven the development of many new VTOL concepts. These vehicles often feature original designs and futuristic shapes. Due to their novelty, the wake characteristics of such aircraft are unknown. However, large wake-induced velocities, should they exist, may be dangerous for any other vehicle evolving in their close proximity. Therefore, improved knowledge about the wakes of VTOL vehicles is needed to guarantee the safety of urban air mobility operations. In this work, we study the wake of three VTOL aircraft in cruise by means of large eddy simulation. We present a two-stage numerical procedure …
A General Coupling Methodology For Unsteady Aerostructural Optimization With Analytic Derivatives, Taylor Mcdonnell, Adam Cardoza, Denis-Gabriel Caprace, Andrew Ning
A General Coupling Methodology For Unsteady Aerostructural Optimization With Analytic Derivatives, Taylor Mcdonnell, Adam Cardoza, Denis-Gabriel Caprace, Andrew Ning
Faculty Publications
Multidisciplinary design optimization offers a comprehensive approach for designing complex aerostructural systems such as wind turbines. Gradient-based multidisciplinary design optimization can be used to optimize complex systems using large numbers of design variables. However, the convergence of gradient-based optimization methods to an optimal solution is highly dependent on the accuracy of the provided derivatives. In this paper, we propose a general method for creating unsteady coupled systems for steady-state, eigenvalue, and time-domain analyses. We then describe how highly accurate derivatives may be obtained from these analyses using a combination of automatic differentiation and analytic methods (including the unsteady adjoint). Finally, …
Durability Of Vacuum Infusion Tooling Produced From Fused Granular Fabrication Additive Manufacturing, Nathan Northrup, Jason Weaver, Andy R. George
Durability Of Vacuum Infusion Tooling Produced From Fused Granular Fabrication Additive Manufacturing, Nathan Northrup, Jason Weaver, Andy R. George
Faculty Publications
Large area additive manufacturing (LAAM) has the capability to create tooling that is lower cost than conventionally manufactured tooling and still has sufficient properties for many applications. A vacuum infusion mold was printed from fiberglass-ABS and evaluated for wear and suitability for small vacuum infusion runs. The mold was designed to accentuate high wear as a “worst case” scenario. The mold was able to produce 10 parts successfully before any noticeable change occurred to the surface finish. By 14 parts, the surface finish had roughened sufficiently that demolding was difficult and resulted in damage to the part. Profilometry measurements showed …
Closed Loop Recycling Of Low Friction Polymers In Fused Granule Fabrication Additive Manufacturing Processes, Neil Thompson, Jason Weaver
Closed Loop Recycling Of Low Friction Polymers In Fused Granule Fabrication Additive Manufacturing Processes, Neil Thompson, Jason Weaver
Faculty Publications
Plastic waste is a critical worldwide problem that impacts additive manufacturing (AM). Extensive research has explored how plastic waste in AM can be reduced by recycling prints into new filament, with varying success. An alternative to filament-based extrusion is “fused granule fabrication” (FGF), which extrudes from pellets or granules. This method is often used for large area additive manufacturing (LAAM) of polymers. This paper expands upon the knowledge base from previous research on LAAM and examines the extent to which PETG can be recycled and reprinted through the same FGF tool without significant loss to its material properties. The metric …
Incorporating High-Fidelity Aerostructural Analyses In Wind Turbine Rotor Optimization, Denis-Gabriel Caprace, Adam Cardoza, Andrew Ning, Marco Mangano, Sicheng He, Joaquim R. R. A. Martins
Incorporating High-Fidelity Aerostructural Analyses In Wind Turbine Rotor Optimization, Denis-Gabriel Caprace, Adam Cardoza, Andrew Ning, Marco Mangano, Sicheng He, Joaquim R. R. A. Martins
Faculty Publications
s demand grows for wind turbines with larger blades, the design of future wind turbines must account for multi-physical interactions and an ever-increasing number of design load conditions. One aspect, aerostructural coupling, calls for design tools that are both accurate and computationally efficient. In this paper, we present a combined-fidelity approach that couples high-fidelity computational fluid dynamics and computational solid mechanics simulations, with a conventional aeroelastic turbine modeling tool based on blade element momentum and beam theories. The approach is integrated into a multidisciplinary optimization framework. It takes advantage of the high-fidelity tightly-coupled aerostructural simulations to evaluate the rotor power …