9305441 Seebaugh Measurements of aerosol made from aircraft sampling platforms are essential to study the ozone depletion and climatic effects of airborne particles. Current aircraft aerosol inlets fail to achieve samples which are representative of the aerosol in the ambient atmosphere. The difficulty arises from the degree of slowing required between the free air stream and the entrance to the sampling device or instrument. Done incorrectly, this slowing can lead to significant inertial enrichment of the aerosol or to significant losses due to turbulent deposition within the inlet. During the initial portion of this project diffusers with useful area ratios will be built and turbulence will be controlled with boundary layer suction. Aerosol deposition studies will be done to demonstrate that the reduced turbulence in the inlet is accompanied by increases in particle transmission through the diffuser. In the second year, an aerodynamic pumping system to provide the needed suction will be designed. The basis for this design will involve either contouring the leading edge of the inlet to provide insensitivity to angle of attack or adding a shroud around the diffuser. Wind tunnel experiments will be used to verify that the internal and external flows behave as expected. The product will be an inlet that is ready for testing on aircraft. ***
