An investigation of the unsteady aerodynamic forcing functions generated by an upstream inlet guide vane row (IGV) is performed. The focus of the study is to investigate the effects of blade count, axial location and span on the IGV generated forcing function. Experimental data is obtained from an isolated IGV row using a high-speed compressor rig as a flow generator. Measurement of the flow field is acquired by placing a circumferential traverse assembly (CTA) downstream of the IGV row. The CTA provides flow field measurements by using two different types of total pressure rakes located at three different axial distances. A linear actuator is used to move the CTA circumferentially so that the IGV generated wakes can be measured. The experiment is performed at 100% design flow and an inlet Mach number of 0.57. A vortical gust analysis is then performed on both the core and boundary layer measured wakes in order to analyze the downstream propagating forcing function. The results show that span and axial location have a significant influence on the vortical forcing function, especially in the near wall regions. The investigation also revealed that the 12% IGV chord axial location contained the highest amount of harmonic content, as well as, the largest overall harmonic magnitudes. Blade count effects were most prominent at the 12% axial location and the 40 IGV configuration produced the largest harmonic magnitudes. In general, the first harmonic remained relatively constant for each axial location, while the amount of higher harmonic content was shown to decrease with increased axial distance. NomenclatureD* n -Vortical gust coefficient k -Gust wave number U -Mean absolute velocity vector vv -Perturbation velocity vector t -Time Subscripts ν -Vortical η -Harmonic number

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