Browsing by Subject "Pistons"
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Item Acoustic radiation from baffled planar sources: a series approach(Texas Tech University, 1999-08) Akkaya, NadirThe acoustic radiation from harmonically vibrating planar sources (pistons and thin plates) is investigated. Triangular, rectangular, circular, and elliptical sources are studied. Clamped and simply supported boundary conditions are considered for plates. The farfield acoustic pressure, the acoustic intensity, and the acoustic power expressions are obtained analytically. Two different approaches are used to find the acoustic power for some cases, and the results are compared. The intensity and power expressions are the time-averaged ones, and the latter is applicable only to sufficiently low frequency of vibrations. Finally, the dependence of the results on various design parameters, such as frequency of vibration and source geometry, is investigated.Item Friction force measurement and analysis of the rotating liner engine(2005) Kim, Myoungjin; Matthews, Ronald D.As emissions regulations become more stringent and fuel prices increase at a significant rate, the fuel efficiency of piston engines becomes more important than ever. Since most of the engine’s friction losses are from the piston/ring assembly, it is indispensable to reduce the piston/ring assembly friction for better fuel economy. The Rotating Liner Engine (RLE) was developed to remove the boundary lubrication of the piston/ring assembly friction through cylinder liner rotation. Even though the RLE was initially developed mainly by Dr. Dardalis several years ago, the friction reduction effect of the RLE was not confirmed except via preliminary motoring tests using a crude dynamometer. The main purpose of this dissertation is to confirm the RLE effect on piston assembly friction reduction using sophisticated measurement methods. Three different friction measurement methods were applied in measuring the friction force difference between a baseline engine and a prototype RLE. Through the use of three different friction measurement methods, the friction reduction of the RLE has been confirmed via this dissertation research and each of the friction measurement methods is also compared based on its measurement results. The analysis of the friction mechanism of the baseline engine was performed using the instantaneous IMEP method and a commercial simulation program called RINGPAK. Through the use of experimental methods and the simulation, the friction mechanism of the piston/ring assembly is analyzed. The limitation of the experimental and the calculation methods is also discussed.