Radian Belu

Sub‐kilometer dynamical downscaling of near‐surface winds in complex terrain using WRF and MM5 mesoscale models

configured with horizontal grid spacing ranging from 27 km in the outermost telescoping to 333 m in the innermost domains and verified with observations collected at four 50-m towers in west-central Nevada during July and December 2007. Moment-based and spectral verification metrics showed that the performance of WRF was superior to MM5. The modeling results were more accurate at 50 m than at 10 m AGL. Both models accurately simulated the mean near-surface wind shear; however, WRF (MM5) generally overestimated (underestimated) mean wind speeds at these levels. The dispersion errors were the dominant component of the root-mean square errors. The major weakness of WRF was the overestimation of the intensity and frequency of strong nocturnal thermally driven flows and their sub-diurnal scale variability, while the main weaknesses of MM5 were larger biases, underestimation of the frequency of stronger daytime winds in the mixed layer and underestimation of the observed spectral kinetic energy of the major energy-containing motions. Neither of the verification metrics showed systematic improvement in the models’ accuracy with increasing the horizontal resolution and the share of dispersion errors increased with increased resolution. However, a profound improvement in the moment-based accuracy was found for the mean vertical wind shear and the temporal variability of wind speed, in particular for summer daytime simulations of the thermally driven flows. The most prominent spectral accuracy improvement among the primary energy-containing frequency bands was found for both models in the summertime diurnal periods. Also, the improvement for WRF (MM5) was more (less) apparent for longer-than-diurnal than for sub-diurnal periods. Finally, the study shows that at least near-kilometer horizontal grid spacing is necessary for dynamical downscaling of near-surface wind speed climate over complex terrain; however, some of the physics options might be less appropriate for grid spacing nearing the scales of the energy-containing turbulent eddies, i.e., resolutions of several hundred meters. In addition to the effects of the lower boundary, the accuracy of the lateral boundary conditions of the parent domains also controls the onset and evolution of the thermally driven flows.

Statistical and Spectral Analysis of Wind Characteristics Relevant to Wind Energy Assessment Using Tower Measurements in Complex Terrain

The main objective of the study was to investigate spatial and temporal characteristics of the wind speed and direction in complex terrain that are relevant to wind energy assessment and development, as well as to wind energy system operation, management, and grid integration. Wind data from five tall meteorological towers located in Western Nevada, USA, operated from August 2003 to March 2008, used in the analysis. The multiannual average wind speeds did not show significant increased trend with increasing elevation, while the turbulence intensity slowly decreased with an increase were the average wind speed. The wind speed and direction were modeled using the Weibull and the von Mises distribution functions. The correlations show a strong coherence between the wind speed and direction with slowly decreasing amplitude of the multiday periodicity with increasing lag periods. The spectral analysis shows significant annual periodicity with similar characteristics at all locations. The relatively high correlations between the towers and small range of the computed turbulence intensity indicate that wind variability is dominated by the regional synoptic processes. Knowledge and information about daily, seasonal, and annual wind periodicities are very important for wind energy resource assessment, wind power plant operation, management, and grid integration.

Advancing sustainable engineering practice through education and undergraduate research projects

Major challenges such as energy, food, water, environment, health and so many more have never been more prominent than they are today. Engineers and educators, as problem solvers should be addressing these issues and challenges in sustainable ways. They have an enormous opportunity to help create a more sustainable world. Technology problems interconnecting sustainability challenges such as climate change, loss of biodiversity, environmental pollution, economic and social instability are becoming increasingly major concerns for mankind. However, the engineers and scientists have failed on large extend to fully address the sustainability issues. It was also found that engineering graduates do not possess necessary skills to tackle sustainability related problems. Engineering practice and education are changing as social expectations and conditions for engineering practice change too. Students have the responsibility and opportunity to continue improving our life while reducing or even reversing the negative impacts that our industrial society is having on the environment. Current engineering curricula are not equipping them to properly deal with these challenges due to little integration of sustainable and green design strategies and practice. Transforming higher education curricula for sustainable development is a tough challenge, dealing with the complexness of sustainability concepts and integration into engineering education. Teaching students the sustainability principles and equipping them with necessary tools help them to make better choices on materials and energy use, or design. These concepts and methods are still relatively new to engineering curriculum and are not an established practice for most of such programs. Meanwhile, today’s students have a strong desire to improve the world through their work, and sustainability connects with these interest and motivations. However, students’ hunger for knowledge often outstrips what is available in their courses and the experiences of their professors. Furthermore, to make sustainable design compelling to a wider base of engineering students, we need to craft sustainable design in terms of mainstream design problems that are important, cutting-edge, and achievable. Then we need to help them how to effectively deal with environmental and societal needs and constraints as part of their core design process. The paper highlights the process required for embedding sustainability and green design into our programs, curriculum design, implementation and impediments to surmount for sustainability and green design in engineering education. This was done through a project-based approach, developing three new courses and appropriate changes in a number of existing courses. The skill requirements were studied and finally the list of subjects, topics, teaching and learning methods are identified and discussed in this paper.Copyright

Infusion of Green Energy Manufacturing Into Engineering and Technology Curricula

This paper discusses a joint educational effort that incorporates sustainability in engineering and technology curricula at Drexel University (DU) and University of Texas at El Paso (UTEP). A critical component of a national “green industries/green jobs” effort is to motivate our citizenry to become proficient in STEM and associated manufacturing fields and societies, thus ensuring we have a 21st century workforce. Sustainable engineering is about design that recognizes the constraints applied by natural resources and the environmental system. The needs for engineering students and practicing engineers to understand sustainability concepts and concerns have been noted by many educators, scientists or engineers, and it is the philosophy of the authors that all engineering students need to become versed in sustainability ideas. This paper describes key factors in enhancing the ability of future engineering graduates to better contribute to a more sustainable future, preserving natural resources and advancing technological and societal development. Two approaches are used to incorporate sustainability into the undergraduate engineering and technology curricula that can be adopted or adapted by science and engineering faculty for this purpose. The two approaches described in the paper include: (1) redesigning existing courses through development of new materials that meet the objectives of the original courses and (2) developing upper division elective courses that address specific topics related to sustainability, such as green manufacturing, clean energy, and life-cycle assessment. The efforts presented in the paper also include an increase in social responsibility, development of innovative thinking skills, better understanding of sustainability issues, and increasing students’ interests in the engineering and technology programs. Projects, included in the senior courses or in the senior design project course sequence have been also part of them.Copyright

Green Energy Manufacturing Laboratory Development for Student Learning Experience on Sustainability

This paper discusses the development of a green energy manufacturing laboratory for student learning experience in the emerging fields of renewable energy and green manufacturing. The development involves a creation of a series of experiments to stimulate discoveries and developments that promise to sustain a wave of new technological innovations on energy and manufacturing throughout the world. The needs for engineering students and practicing engineers to understand sustainability concepts and concerns have been noted by educators, scientists or engineers and all engineering students need to become versed in sustainability ideas. This paper describes key factors in enhancing the ability of future engineering graduates to better contribute to a more sustainable future, preserving natural resources and advancing technological development. Two main components are used to incorporate sustainability into the green energy manufacturing laboratory, including: (1) renewable energy and (2) manufacturing energy efficiency. The efforts presented in the paper also include life-cycle assessment, development of innovative thinking skills, better understanding of sustainability issues, and increasing students’ interests in the engineering and technology programs. A concluding section discusses laboratory development for student hands-on learning experience within the context of a project. The paper will present the how it establishes its long-term sustainability and support through a variety of mechanisms including the energy mission, the award of federal grants, program projects, private foundation support, partnerships, and university-based investments. The GEM/Institute/Community College research model and the supporting the hardware, software and middleware are being installed, developed and enabled by the joint project between two universities in the nation.Copyright

Sustainable and Renewable Energy Undergraduate Research

Energy is a continuous driving force for the social and technological prospective developments and a vital and essential ingredient for all human transactions. The world is facing an energy “crisis”, due to limited fossil fuel resources, growing energy demand and population. All these facts led to and increased interests in renewable energy sources and green manufacturing. Equipping engineering students with the skills and knowledge required to be successful global engineers in the 21st century is one of the primary objectives of academic educators. Enabling students to practice self-directed learning, find design solutions that are sustainable, and helping them recognize that they are part of a global community are just of few of our educational goals. Project-based learning provides the contextual environment making learning exciting and relevant, providing opportunities to explore technical problems from systems-level perspectives, with an appreciation for the inter-connectedness of science principles. The quest for knowledge is the driving force behind education no matter what field is being studied. This means a lot of reading from textbooks, completion of assignments, exams, lectures but quite little of this work involves original research. Active research experience is one of the most effective ways to attract and retain talented undergraduates in science and engineering. At our institutions, we are regularly modifying curriculum content to embrace sustainability and green energy concepts in learning outcomes. However this crosses over between a numbers of multi-disciplinary, multidimensional study areas that include philosophy and ethics. Consequently a major challenge for us is to encourage engineering students whose primary focus is purely technical to include sustainability and renewable energy topics in their designs. To join into this effort of equipping the future engineers and technologists with renewable energy background, we developed a set of project-based courses related to these topics and include them also in our senior project design course sequence. The main objectives of these curricula changes are to provide students with theoretical and practical knowledge reinforced by hands-on experience. These projects are also good examples of multi-disciplinary cooperation of different engineering disciplines as well as providing valuable hands-on and research experience. This paper presents the changes in the course structure, sample of projects, student survey of the course, as well as plans and expectations for future success. We are also discussing here the project team structure, plan and management, component selection, system simulation, and experimental result.Copyright