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This paper will present the scope of an NASA program aimed at improving the design and evaluation techniques relative to stall/spin characteristics of general-aviation aircraft. The program encompasses analytical studies, full-scale and model wind-tunnel tests, radio-control model, and full-scale flight tests. Initial spin-tunnel results of several tail designs on a representative light airplane will be discussed.

Concern about the consequences of fuel dilution on engine oil properties are intensifying due to the increasing use of E25 and E85 fuel in passenger cars. Notably, such concerns are about the effect of emulsion formation and stability in crankcase oils by E25 or E85 fuel and water dilution on vehicle operation at cold-start conditions. Different types of Viscosity Index Improver (VII) chemistries were evaluated for their effects on emulsion formation and engine oil characteristics. Emulsions were prepared with fresh and used passenger car motor oils using the ASTM D7563 method for emulsion retention. The emulsion properties were evaluated after storage for 24 hours at two different temperatures. Separate oil/gasoline and emulsion (ethanol/water/oil) phases were observed for fresh oil emulsions. None of the emulsions exhibited a separate water phase, regardless of the type of VII in the oil.

Electric vehicles offer cleaner transportation with lower emissions, thus their increased popularity. Although, electric powertrains contribute to quieter vehicles, the shift from internal combustion engines to electric powertrains presents new Noise, Vibration, and Harshness challenges. Unlike traditional engines, electric powertrains produce distinctive tonal noise, notably from motor whistles and gear whine. These tonal components have frequency content, sometimes above 10 kHz. Furthermore, the housing of the powertrain is the interface between the excitation from the driveline via the bearings and the radiated noise (NVH). Acoustic features of the radiated noise can be predicted by utilising the transmitted forces from the bearings. Due to tonal components at higher frequencies and dense modal content, full flexible multibody dynamics simulations are computationally expensive.