Smaaart task order: task title: aeroacoustic measurements of a leading-edge slat 1.0 introduction/background: nasas subsonic fixed wing project conducts research with the goal of improving…

Smaaart task order: task title: aeroacoustic measurements of a leading-edge slat 1.0 introduction/background: nasas subsonic fixed wing project conducts research with the goal of improving prediction methods and technologies towards lower aircraft noise, lower emissions, and higher performance of subsonic aircraft for the next generation air transportation system. Development of improved prediction methods and technologies for a reduced noise signature is, therefore, one of the important focal areas for the project. To that end, the project strategy includes provisions for novel test methods and validated prediction tools that can be used to improve system tradeoffs for advanced concepts capable of meeting longer-term noise goals. Specifically, foundational research is performed in the project to establish validation data for computational tools and to develop noise prediction and reduction technologies for propulsive (i.e., engine related) and airframe noise sources. With the advent of quieter, ultra-high-bypass-ratio engines, flow unsteadiness in the vicinity of various airframe components has emerged as an important contributor to the overall noise signature of subsonic commercial transports during their landing approach. The major sources of airframe noise include high-lift devices (i.e., leading-edge slat and trailing-edge flaps) and the aircraft undercarriage (i.e., landing gear). NASA has an active program of research related to each of these noise sources. In the context of slat noise, NASA s langley research center is engaged in a coordinated series of investigations that combine high-fidelity numerical simulations and detailed wind tunnel measurements of a generic, unswept, 3-element, high-lift configuration (GFI items 5.1-5.5). The goal of these investigations is to provide a validated predictive capability that would enable the identification of the dominant noise source mechanisms and, ultimately, help develop physics inspired concepts for reducing the far-field acoustic intensity. The experimental component of this research has focused on a generic, unswept, 3-element, high-lift configuration. The 30P30N configuration has been used for various measurements of the unsteady flow near the slat in nasas basic aerodynamic research tunnel (bart). Primary data obtained thus far includes particle image velocimetry (PIV) measurements of the unsteady flow field within the slat cove and in the vicinity of the slat trailing edge. Both planar and stereo PIV measurements have been obtained to characterize the planar and cross-plane structures within this flow. This data has been valuable for validating the near-field simulations of unsteady flow near the slat and has been used by researchers at NASA as well as elsewhere. The purpose of this effort is to obtain several extra measurements that are still required to enable the goal of validated physics based predictions of slat noise. To bridge this GAP, a new slat model instrumented with dynamic pressure transducers is being fabricated at NASA. Because of acoustic reflections within a closed wall wind tunnel, IT is expected that the goal of benchmark quality acoustic measurements will only be met within an open jet facility. However, NASA is amenable to the measurements being obtained in a different type of facility. Unfortunately, the NASA facility where such measurements can be obtained will not be available within the targeted timeframe, specifically to allow the data to be used by participants in the second aiaa workshop on benchmark problems for airframe noise computations (banc-II), which will be held in june 2012. This statement of work (SOW) is directed at the various tasks related to the aeroacoustic measurements of the 30P30N slat within a facility outside of NASA. 2.0 scope / objective(s): the scope of this task order is to generate a benchmark quality experimental database of aeroacoustic measurements of a leading edge slat usin