Michael R. Motley
University of Washington
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Featured researches published by Michael R. Motley.
Volume 7: Ocean Space Utilization; Professor Emeritus J. Randolph Paulling Honoring Symposium on Ocean Technology | 2014
Michael R. Motley; Ramona B. Barber
As the need for clean and renewable energy becomes greater, alternative energy technologies are becoming more and more prevalent. To that end, there has been a recent increase in research on marine hydrokinetic turbines to assess their potential as a reliable source of energy production and to expedite their implementation. These turbines are typically constructed from fiber reinforced composites and are subject to large, dynamic fluid forces. One of the benefits of composite materials is that the bend-twist deformation behavior can be hydroelastically tailored such that the blades are able to passively change their pitch to adapt to the surrounding flow, creating a nearly instantaneous control mechanism that can improve system performance over the expected range of operating conditions. These improvements include increasing energy capture, reducing instabilities, and improving structural performance. Practical constraints, however, lead to limitations in the scope of these performance enhancements and create tradeoffs between various benefits that can be achieved. This paper presents a numerical investigation into the capability of passive pitch control and combined active/passive pitch control to modify the performance of horizontal axis marine turbines with proper consideration of practical restrictions.Copyright
International Journal of Rotating Machinery | 2014
Michael R. Motley; Brant R. Savander; Yin Lu Young
Surface Effect Ships (SES) are a promising fuel-efficient ship technology that typically carry most of their weight on an air cushion. To accommodate its shallow draft and slender side hulls and to absorb the high thrust and power required for high-speed applications, waterjets are typically used as the primary propulsion system. A waterjet typically has a flush mounted inlet and operates under complex three-dimensional flow conditions that result in highly nonuniform flows. The objectives of this work are to quantify the flow nonuniformity and the influence of unsteady cavitation on the response of an SES-waterjet system and to investigate the effect of flow nonuniformity and cavitation on the dynamic hydroelastic response of the rotor and stator blades. The results showed that as the flow advances through the pump, the ingested boundary layer from the bottom of the side hulls becomes increasingly nonuniform, particularly between the rotor and stator. The flow nonuniformity was shown to result in hydrodynamic load fluctuations and high side forces on the rotor and stator blades. The unbalanced blade loads lead to the generation of net upward forces on the pump casing and shaft. Flow nonuniformity also leads to unsteady cavitation and unsteady blade stresses and deformations.
Composite Structures | 2014
Michael R. Motley; Ramona B. Barber
Applied Mechanics Reviews | 2016
Yin Lu Young; Michael R. Motley; Ramona B. Barber; Eun Jung Chae; Nitin Garg
Journal of Fluids and Structures | 2016
Ramona B. Barber; Michael R. Motley
Coastal Engineering | 2018
Xinsheng Qin; Michael R. Motley; Nasser Marafi
Archive | 2019
Ramona B. Barber; Michael R. Motley
arXiv: Mathematical Software | 2018
Xinsheng Qin; Randall J. LeVeque; Michael R. Motley
Natural Hazards and Earth System Sciences | 2018
Xinsheng Qin; Michael R. Motley; Randall J. LeVeque; Frank I. Gonzalez; Kaspar Mueller
Composite Structures | 2018
Pavel F. Babuska; Richard Wiebe; Michael R. Motley