Identifying Slowly-Varying and Turbulent Wind Features for Flight Loads Analyses

A methodology developed to determine the spectral boundary between the slowly-varying components and the more rapidly varying, or turbulent components, of measured wind profiles is presented. Pairs of measured wind velocity versus altitude profiles from the Eastern and Western launch ranges of the United States were used to establish the vertical wavelengths which could no longer be considered slowly varying over discrete time intervals. Analyses were performed for wind pairs that were 30, 60, 90, and 120 minutes apart. The wavelength boundary between slowly-varying and turbulent wind features as a function of time interval is presented. The results of this work make it now possible to identify and extract the slowly-varying and/or turbulent wind features, as needed for a specific day-of-launch flight loads analysis, for these two launch facilities.