Link Fellowship Awardees For 2011
Phillip K. Chiu
Department of Mechanical and Aerospace Engineering
University of California, Los Angeles
Next-Generation wind turbine blades: Transformative
design of inboard cross-sections
Research Advisor: Professor Richard Wirz
Next-generation wind turbine blades: Transformative design of inboard cross-sections
As wind turbine rotor blades have grown in size, so have the structural loads they must endure. Blade bending stresses and structural dynamic response have become of increasing concern, requiring thick inboard (near hub) airfoil cross-sections which have good structural but poor aerodynamic performance.
Transformative designs of inboard blade sections can improve both structural and aerodynamic performance of next-generation turbine blades. Preliminary investigation by this group has shown that using a biplane airfoil configuration in the inboard section can increase stiffness by 10 times and improve lift while reducing drag. These characteristics have a positive impact on power output, availability, startup speed, and blade fatigue life.
This research explores how blade design parameters affect the aerodynamic and structural performance of the turbine. The goals of this research are to
- Quantify the effects of cross-sectional parameters on the aerodynamic performance and structural dynamic response of wind turbines,
- Develop a fast aeroelastic code to perform this parametric analysis, and to
- Design innovative blade cross-sections that improve aerodynamic and aeroelastic performance of wind turbines blades.
Blade designs resulting from this research could improve the performance of mid- and large-size turbines, and enable the development of ultra-large high-payoff 8–10 MW turbines
James Henry Nelson
Chemistry/Energy and Resources
University of California at Berkeley
Deployment of an Inexpensive, Reliable, and Low Carbon
Electric Power System Requires New Modeling Tools
Research Advisor: Professor Daniel Kammen
Decarbonizing electricity production is essential to reducing greenhouse gas emissions. Exploiting intermittent renewable energy resources demands a new class of power system planning models with high temporal and spatial resolution. My research centers on an emerging mixed-integer linear programming model named ‘SWITCH’ that analyzes generation, storage and transmission capacity expansion for North America under various policy scenarios and hourly resolution at minimal cost. We have already used SWITCH to demonstrate that carbon emission reductions from the Western North American electric power sector can be achieved at lower costs than have been previously projected. My doctoral work will expand the model to the entirety of the United States and Canada, in hopes that similar conclusions can be made for a larger geographic area. Our model will provide strategies to policy makers and electric power sector planners that can lead to inexpensive, reliable, and low carbon intensity power.
Leslie Esther O'Leary
Chemistry and Chemical Engineering
California Institute of Technology
Interfaces for the conversion of solar energy to chemical fuel:
GaP surface functionalization
Research Advisor: Nathan S. Lewis
Gallium Phosphide, or GaP, is an earth abundant semiconductor with a wide band-gap of 2.26 eV. The wide band-gap is not ideal for a single junction photovoltaic, however it still absorbs in the visible region, making it terrestrially relevant. Furthermore, and more importantly, it can singly provide the necessary photovoltage for many fuel-forming reactions that smaller band-gap semiconductors, such as Si, cannot do alone. GaP is an interesting material because it is lattice matched to Si, making for a convenient epitaxial substrate and pair in a tandem configuration.
III-V semiconductor surface chemistry is not well explored - even basic surface etching. If this promising material is to be used for solar energy to fuel conversion, the interface must be understood and controlled. Poor interfacial control mainly leads to corrosion of III-V semiconductors at SC/liquid junctions. Losses also come through surface electronic trap-states, incorrect band-edge alignment, and reaction overpotential at the surface. In depth studies of surface electronic trap-state density, band-edge position, and stability after various etchants and chemically passivating surface treatments will increase the versatility of III-V semiconductors in photoelectrochemical cells and advance the progress of integration of this and other similar III-V materials into solar energy conversion devices.