Version 1.10 of the TurbSim Code is now available on the NWTC Design Codes webpage.
With the release of Version 1.10, a new model GP_LLJ (Great Plains Low-Level Jet) is included that simulates flow conditions associated with the large vertical shears and coherent turbulence encountered within and beneath Great Plains low-level jet streams. A low-level jet stream (LLJ) is a current of higher speed air that usually forms at night near the ground and is characterized by strong vertical wind shear beneath a wind speed maximum that typically occurs at heights between 50 and 500 m AGL.The GP_LLJ model reflects conditions seen over the Great Plains with and without the presence of a low-level jet stream that occurs at a height between 70 and 490 m AGL.
Local turbulence scaling and low-level jet vertical wind profiles used with the GP_LLJ model have been derived from measurements collected on a 120-m tower and with a medium range Doppler acoustic wind profiler (SODAR) located in the southwestern Great Plains near Lamar, Colorado. The GP_LLJ model allows the user to specify the jet height and peak wind speed (intensity) or to let the code randomly choose a jet height and/or wind speed based on the other specified boundary conditions. The GP_LLJ model produces both wind speed and direction profiles that can be extended down to a height of 3 m AGL when the JET profile option is chosen.