Thermal transport processes in stable boundary layers

ORAL

Abstract

Using the 200-m tower data (Reese, Texas), profiler and Mesonet data, and WRF runs, a 4-dim model is introduced which summarizes the main features of the Low Level Jet (LLJ) in stable boundary conditions over the aforementioned region and shows its patterns along the year. We also demonstrate the importance of LLJs for wind energy production. It has been observed that during a LLJ event the level of turbulence intensities and TKE are significantly much lower than those during unstable conditions. The major salient results from this study include: the vertical shears in the LLJ are very large at the current wind turbine heights, causing higher static and cyclical aerodynamic loads. The WRF model has accurately captured the beginning and end of the LLJ event; however, the local maximum wind speed at the LLJ ``nose'' has been under-predicted by approximately 15{\%}, which highlights the difficulties WRF still faces in predicting this phenomenon. Furthermore, power spectra and time-autocorrelations of thermal fluctuations will help us in the understanding of the thermal coherent structures involved in moderate and strong LLJ.

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Authors

  • Walter Gutierrez

    Texas Tech University, Lubbock, TX, National Wind Resources Center, Texas Tech University, Lubbock, TX, USA

  • Guillermo Araya

    Texas Tech University, Texas Tech University, Lubbock, TX, National Wind Resources Center, Texas Tech University, Lubbock, TX, USA, Department of Mechanical Engineering, Texas Tech University

  • Praju Kiliyanpilakkil

    Department of Marine, Earth, and Atmospheric Sciences; North Carolina State University, Raleigh, NC, USA

  • Sukanta Basu

    Department of Marine, Earth, and Atmospheric Sciences; North Carolina State University, Raleigh, NC, USA

  • Arquimedes Ruiz-Columbie

    Texas Tech University, Lubbock, TX, National Wind Institute, Texas Tech University, Lubbock, TX, USA, Texas Tech University

  • Luciano Castillo

    Texas Tech University, Texas Technical University, Texas Tech University, Lubbock, TX, National Wind Resources Center, Texas Tech University, Lubbock, TX, USA, Department of Mechanical Engineering, Texas Tech University, Texas Tech Univ