Effect of Surface Pressure Integration Methodology on Launch Vehicle Buffet Forcing Functions

Abstract

The 2014 test of the Space Launch System (SLS) Rigid Buffet Model conducted at the NASA Langley Transonic Dynamics Tunnel employed an extremely high number of unsteady pressure transducers. The high channel count provided an opportunity to examine the effect of transducer placement on the resulting buffet forcing functions (BFFs). Rings of transducers on the forward half of the model were employed to simulate a single-body vehicle. The impact of transducer density, circumferential distribution, and loss of a single transducer on the resulting BFFs were examined. Rings of transducers on the aft half of the SLS model were employed to examine the effect of transducer density and circumferential distribution on BFFs for a multibody configuration. Transducer placement considerations with respect to model size, facility infrastructure, and data acquisition system capabilities, which affect the integration process, are also discussed. Notice to ReadersThe predicted performance and certain other features and characteristics of the Space Launch System vehicle are defined by the U.S. Government to be Sensitive But Unclassified (SBU). Therefore, values in plots and figures have been either removed or normalized to arbitrary values.