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Full-Text Articles in Engineering
Review Of Computational Models For Large-Scale Mdao Of Urban Air Mobility Concepts, Darshan Sarojini, Marius L. Ruh, Jiayao Yan, Luca Scotzniovsky, Nicholas C. Orndorff, Ru Xiang, Han Zhao, Joshua J. Krokowski, Michael Warner, Sebastiaan Pc Van Schie, Ashley Cronk, Alexandre T. R. Guibert, Jeffrey T. Chambers, Lauren Wolfe, Rachel Doring, Robin Despins, Cibin Joseph, Ryan Anderson, Andrew Ning, Hyunjune Gill, Seongkyu Lee, Zeyu Cheng, Zhi Cao, Chunting Mi, Y Shirley Meng, Christopher Silva, Jiun-Shyan Chen, H. Alicia Kim, John T. Hwang
Review Of Computational Models For Large-Scale Mdao Of Urban Air Mobility Concepts, Darshan Sarojini, Marius L. Ruh, Jiayao Yan, Luca Scotzniovsky, Nicholas C. Orndorff, Ru Xiang, Han Zhao, Joshua J. Krokowski, Michael Warner, Sebastiaan Pc Van Schie, Ashley Cronk, Alexandre T. R. Guibert, Jeffrey T. Chambers, Lauren Wolfe, Rachel Doring, Robin Despins, Cibin Joseph, Ryan Anderson, Andrew Ning, Hyunjune Gill, Seongkyu Lee, Zeyu Cheng, Zhi Cao, Chunting Mi, Y Shirley Meng, Christopher Silva, Jiun-Shyan Chen, H. Alicia Kim, John T. Hwang
Faculty Publications
The advent of Urban Air Mobility (UAM) has necessitated a paradigm shift in aircraft design from traditional regression methods to physics-based analysis and the use of modern computational methods. This paper explores the intricacies of UAM aircraft design, acknowledging the limitations of historical empirical equations and advocating for the use of physics-based tools in the early stages of the design process. It underscores the importance of Multidisciplinary Design, Analysis, and Optimization (MDAO) as a means to integrate physics-based tools for conceptual design, facilitating decisions on configuration and sizing. The paper presents a comprehensive survey and review of computational models across …
Low-Fidelity Design Optimization And Parameter Sensitivity Analysis Of Tilt-Rotor Evtol Electric Propulsion Systems, Tyler Critchfield, Andrew Ning
Low-Fidelity Design Optimization And Parameter Sensitivity Analysis Of Tilt-Rotor Evtol Electric Propulsion Systems, Tyler Critchfield, Andrew Ning
Faculty Publications
Urban air mobility requires a multidisciplinary approach to tackle the important chal- lenges facing the design of these aircraft. This work uses low-to-mid fidelity tools to model rotor aerodynamics, blade structures, vehicle aerodynamics, and electric propulsion for a tilt-rotor electric vertical takeoff and landing (eVTOL) aircraft. We use gradient-based design optimization and extensive parameter sensitivity analysis to explore the design space and complex tradeoffs of tilt-rotor distributed electric propulsion systems.
Sparsity For Gradient-Based Optimization Of Wind Farm Layouts, Benjamin T. Varela, Andrew Ning
Sparsity For Gradient-Based Optimization Of Wind Farm Layouts, Benjamin T. Varela, Andrew Ning
Faculty Publications
Optimizing wind farm layouts is an important step in designing an efficient wind farm. Optimizing wind farm layouts is also a difficult task due to computation times increasing with the number of turbines present in the farm. The most computationally expensive part of gradient- based optimization is calculating the gradient. In order to reduce the expense of gradient calculation, we performed a study on the use of sparsity in wind farm layout optimization. This paper presents the findings of the sparsity study and provides a method to use sparsity in wind farm layout optimization. We tested this sparsity method by …
Using Blade Element Momentum Methods With Gradient-Based Design Optimization, Andrew Ning
Using Blade Element Momentum Methods With Gradient-Based Design Optimization, Andrew Ning
Faculty Publications
Blade element momentum methods are widely used for initial aerodynamic analysis of propellers and wind turbines. A wide variety of correction methods exist, but common to all variations, a pair of residuals are converged to ensure compatibility between the two theories. This paper shows how to rearrange the sequence of calculations reducing to a single residual. This yields the significant advantage that convergence can be guaranteed and to machine precision. Both of these considerations are particularly important for gradient- based optimization where a wide variety of atypical inputs may be explored, and where tight convergence is necessary for accurate derivative …
A Comparison Of Aerodynamic Models For Optimizing The Takeoff And Transition Of A Bi-Wing Tailsitter, Ryan Anderson, Jacob Willis, Jacob Johnson, Andrew Ning, Randal Beard
A Comparison Of Aerodynamic Models For Optimizing The Takeoff And Transition Of A Bi-Wing Tailsitter, Ryan Anderson, Jacob Willis, Jacob Johnson, Andrew Ning, Randal Beard
Faculty Publications
Electric vertical takeoff and landing (eVTOL) aircraft take advantage of distributed electric propulsion as well as aerodynamic lifting surfaces to take off vertically and perform long-duration flights. Complex aerodynamic interactions and a hard-to-predict transition maneuver from hover to wing-borne flight are one challenge in their development. To address this, we compare three different interaction models of varying fidelity for optimizing the transition trajectory of a biplane tailsitter. The first model accounts for simplified rotor-on-wing interactions using momentum theory, while the other two account for wing-on-wing interactions using a vortex lattice method and rotor-on-wing aerodynamic interactions using blade element momentum theory. …
Optimization Of Turbine Tilt In A Wind Farm, James Cutler, Andrew P.J. Stanley, Jared J. Thomas, Andrew Ning
Optimization Of Turbine Tilt In A Wind Farm, James Cutler, Andrew P.J. Stanley, Jared J. Thomas, Andrew Ning
Faculty Publications
Wind farm power production is significantly affected by upstream turbines creating wakes of slower wind speeds that overlap the rotor swept areas of downstream turbines. By optimizing the tilt angle of the turbines in a farm, wakes may be deflected away from downstream turbines, increasing the overall energy production. In this study, we optimized the tilt angle of turbines in a wind farm to maximize energy production. We used an analytic wake model modified for gradient-based optimization to consider wake deflection from tilt. We considered optimizing the tilt angle of each turbine assuming that it remained fixed for the lifetime …
Efficient Incorporation Of Fatigue Damage Constraints In Wind Turbine Blade Optimization, Bryce Ingersoll, Andrew Ning
Efficient Incorporation Of Fatigue Damage Constraints In Wind Turbine Blade Optimization, Bryce Ingersoll, Andrew Ning
Faculty Publications
Wind turbine design is a challenging multidisciplinary optimization problem, where the aerodynamic shapes, structural member sizing, and material composition must all be determined and optimized. Some previous blade design methods incorporate static loading with an added safety factor to account for dynamic effects. Others incorporate dynamic loading, but in general limit the evaluation to a few design cases. By not fully incorporating the dynamic loading of the wind turbine, the final turbine blade design is either too conservative by overemphasizing the dynamic effects or infeasible by failing to adequately account for these effects. We propose an iterative method that estimates …
Takeoff And Performance Tradeoffs Of Retrofit Distributed Electric Propulsion For Urban Transport, Kevin Moore, Andrew Ning
Takeoff And Performance Tradeoffs Of Retrofit Distributed Electric Propulsion For Urban Transport, Kevin Moore, Andrew Ning
Faculty Publications
While vertical takeoff and landing aircraft have shown promise for urban air transport, distributed electric propulsion on existing aircraft may offer immediately implementable alternatives. Distributed electric propulsion could potentially decrease takeoff distances enough to enable thousands of potential inter-city runways. This conceptual study explores the effects of a retrofit of open-bladed electric propulsion units. To model and explore the design space we use blade element momentum method, vortex lattice method, linear-beam finite element analysis, classical laminate theory, composite failure, empirically-based blade noise modeling, motor and motor-controller mass models, and gradient-based optimization. With liftoff time of seconds and the safe total …
Improving The Floris Wind Plant Model For Compatibility With Gradient-Based Optimization, Jared Thomas, Pieter Gebraad, Andrew Ning
Improving The Floris Wind Plant Model For Compatibility With Gradient-Based Optimization, Jared Thomas, Pieter Gebraad, Andrew Ning
Faculty Publications
The FLOw Redirection and Induction in Steady-state (FLORIS) model, a parametric wind turbine wake model that predicts steady state wake characteristics based on wind turbine position and yaw angle, was developed for optimization of control settings and turbine locations. This paper provides details on the recent changes made to the FLORIS model to make the model more suitable for gradient-based optimization. Changes to the FLORIS model were made to remove discontinuities and add curvature to regions of non-physical zero gradient. Exact gradients for the FLORIS model were obtained using algorithmic differentiation. A set of three case studies demonstrate that using …
Optimization Under Uncertainty For Wake Steering Strategies, Julian Quick, Jennifer Annoni, Ryan King, Katherine Dykes, Paul Fleming, Andrew Ning
Optimization Under Uncertainty For Wake Steering Strategies, Julian Quick, Jennifer Annoni, Ryan King, Katherine Dykes, Paul Fleming, Andrew Ning
Faculty Publications
Wind turbines in a wind power plant experience significant power losses because of aerodynamic interactions between turbines. One control strategy to reduce these losses is known as 'wake steering,' in which upstream turbines are yawed to direct wakes away from downstream turbines. Previous wake steering research has assumed perfect information, however, there can be significant uncertainty in many aspects of the problem, including wind inflow and various turbine measurements. Uncertainty has significant implications for performance of wake steering strategies. Consequently, the authors formulate and solve an optimization under uncertainty (OUU) problem for finding optimal wake steering strategies in the presence …
Polynomial Chaos For The Computation Of Annual Energy Production In Wind Farm Layout Optimization, Santiago Padrón, Andrew P.J. Stanley, Jared Thomas, Juan Alonso, Andrew Ning
Polynomial Chaos For The Computation Of Annual Energy Production In Wind Farm Layout Optimization, Santiago Padrón, Andrew P.J. Stanley, Jared Thomas, Juan Alonso, Andrew Ning
Faculty Publications
Careful management of wake interference is essential to further improve Annual Energy Production (AEP) of wind farms. Wake effects can be minimized through optimization of turbine layout, wind farm control, and turbine design. Realistic wind farm optimization is challenging because it has numerous design degrees of freedom and must account for the stochastic nature of wind. In this paper we provide a framework for calculating AEP for any relevant uncertain (stochastic) variable of interest. We use Polynomial Chaos (PC) to efficiently quantify the effect of the stochastic variables—wind direction and wind speed—on the statistical outputs of interest (AEP) for wind …
Comparison Of Two Wake Models For Use In Gradient-Based Wind Farm Layout Optimization, Jared Thomas, Eric Tingey, Andrew Ning
Comparison Of Two Wake Models For Use In Gradient-Based Wind Farm Layout Optimization, Jared Thomas, Eric Tingey, Andrew Ning
Faculty Publications
Wind farm layout has a significant impact on the productivity of a wind farm. To ensure that the turbines are placed in the most advantageous arrangement, optimization algorithms are often used during the layout design process. Depending on the wake model used for the optimization, optimizing the layout can be time intensive or potentially inaccurate. In this paper we present a comparison of optimization results using two simple wake models, the FLORIS model and the Jensen model. Results highlight some of the key similarities and differences of layout optimization results when different wake models are used.
Gradient-Based Non-Linear Microstructure Design, Brent L. Adams, M. Lyon
Gradient-Based Non-Linear Microstructure Design, Brent L. Adams, M. Lyon
Faculty Publications
The support of this research by the Army Research Office is gratefully acknowledged. M. Lyon is supported by a National Science Foundation Graduate Research Fellowship. Fourier analysis is implemented on the orientation distribution of a polycrystalline microstructure. The linearity and convexity of the Fourier space, with respect to orientation, allows one to consider all possible distributions by considering all linear combinations of single-grain orientations. The limits of the Fourier space are therefore defined by the solutions to a set of linear programming problems. A unique approach to the linear programming, similar to the Krylov subspace methods for obtaining solutions to …
Microstructure-Sensitive Design Of A Compliant Beam, Brent L. Adams, Alisa J. Millar Henrie, B. Henrie, M. Lyon, H. Garmestani, Surya R. Kalidindi
Microstructure-Sensitive Design Of A Compliant Beam, Brent L. Adams, Alisa J. Millar Henrie, B. Henrie, M. Lyon, H. Garmestani, Surya R. Kalidindi
Faculty Publications
BA acknowledges financial support provided by the MRSEC Program of the National Science Foundation under Award Number DMR-9632556. SK acknowledges financial support from National Science Foundation under Award Number CMS-9732699. BA, SK and HG also acknowledge support from the NSF-CIRE program centered at Florida A&M University, facilitating collaborations. Support was also provided by the College of Engineering and Technology at BYU (AH, BH and ML). Computations were performed on the new SGI Origin 2000 supercomputer at Brigham Young University, donated by Ira Fulton. We show that mechanical design can be conducted where consideration of polycrystalline microstructure as a continuous design …