Effect of Diesel-Palm Fatty Acid Distillate Ethyl Ester-Hydrous Ethanol Blend on the Performance, Emissions, and Long-Term Endurance Test on an Unmodified DI Diesel Engine.

In this research, the diesel-palm fatty acid distillate ethyl ester-hydrous ethanol, palm fatty acid distillate ethyl ester, and diesel were studied to investigate the gas emissions and performances of the direct injection diesel engine at different engine loads and engine speeds. At all engine speeds and loads, nitrogen oxide emissions from all fuel blends (D50PE40E10, D40PE50E10, and D30PE60E10) were significantly lower than the baseline diesel. At all engine speeds and engine loads, the fuel blends released less carbon dioxide than the baseline diesel, with the exception of the D30PE60E10 blend. Furthermore, D30PE60E10 diesel was used to test wear for 500 h long-term endurance of diesel engine components. The results indicated that biodiesel in fuel blends may reduce engine component wear by forming a thin coating on the metal surface of the engine component. However, after 100 h of continuous operation with D30PE60E10 blend, the engine cannot be restarted because only a part of the fuel pump had many pores on the surface of the plunger, barrel, delivery valve, and valve holder. However, these components may have to be considered to prevent corrosion when this fuel blend was employed.

Design and performance testing of an ultrasonic linear motor with dual piezoelectric actuators.

In this work, design and performance testing of an ultrasonic linear motor with dual piezoelectric actuator patches are studied. The motor system consists of a linear stator, a pre-load weight, and two piezoelectric actuator patches. The piezoelectric actuators are bonded with the linear elastic stator at specific locations. The stator generates propagating waves when the piezoelectric actuators are subjected to harmonic excitations. Vibration characteristics of the linear stator are analyzed and compared with finite element and experimental results. The analytical, finite element, and experimental results show agreement. In the experiments, performance of the ultrasonic linear motor is tested. Relationships between velocity and pre-load weight, velocity and applied voltage, driving force and applied voltage, and velocity and driving force are reported. The design of the dual piezoelectric actuators yields a simpler structure with a smaller number of actuators and lower stator stiffness compared with a conventional design of an ultrasonic linear motor with fully laminated piezoelectric actuators.