The current methodology for modeling Krueger device noise utilizes individual noise sources and performs a summation of those sources to produce the final sound level predictions. This method has been used to create an accurate prediction tool for numerous airframe components, such as a leading edge slat. In this paper, we examine results from CFD/CAA analyses to illustrate the complex interaction of associated noise sources that affect Krueger device noise. For example, the complex deployment brackets disturb the local flow and form turbulent wakes that influence other noise source mechanisms. Sealing the gap between the Krueger and wing leading edge can significantly affect the strength of noise sources by limiting both the interaction of turbulent eddies with the wing surface and the velocities seen by the brackets. In addition, the Krueger flap rigging position can cause the shear layer shed from its leading edge to impinge upon the storage cavity. This paper discusses in detail how the components of a Krueger flap system interact to affect the overall sound levels of the Krueger device. Future modeling efforts should include the aerodynamics of the whole Krueger device system when estimating the source strength of each component individually.
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