Based on a Jeffcott rotor system with rigid support, the math models of flexural and torsional vibration were built, and their vibration characteristics were concluded. A simulation experiment in this paper was designed about the flexural and torsional vibration of shafts on a simulated turbine generator during network impacts. By analysis, flexural and torsional vibration characteristics were obtained, and the results showed the shafts flexural vibration and torsional vibration were interacted with each other. It was provided that torsional vibration could inhibit the complex shafts exercise. A new idea was suggested that the characteristics of torsion vibration should be considered as the symptom of faults diagnosis
The ultrasonic vibration assisted compression process is analyzed from the viewpoint of the impact dynamics. The typical metal forming patterns are studied based on the theory of wave propagation in solid. The effects of the geometry scale, friction, material parameters, ultrasonic amplitude and ultrasonic frequency on the forming process are analyzed. A combined parameter is proposed to evaluate the impact of the ultrasonic vibration on the specimen. The typical metal forming parttern are demonstrated by the experiment result of the literature.
In this paper electronic control unit (ECU) used in vehicle-used compressed natural gas engine is developed independently. A series of start experiments are done with refitted JL465Q5 engine. Experimental monitoring system is developed as an interface connecting staff and single chip. Speed acquisition system is developed to record start process accurately in real time. The test results indicate that, more concentrated mixture is necessary when start speed is lower. Higher engine coolant temperature is conductive to cold start for natural gas engine. Multiple ignition control and ignition energy improvement is conductive to start successfully for natural gas engine. The results showed that electronic control unit (ECU) and speed acquisition system developed independently is practical and feasible.
Aiming at issues of the modern embedded turbine supervisory instruments such as simplistic function, weak process power, low efficiency and so on, the technique of double CPUs with the cores of Intel PXA270 and Cyclone II EP2C20 microprocessors is employed in the present design. With embedded linux operating system and the developing platform of Qt software implemented, important functions such as data acquisition, data transfer based on TCP/IP protocols, display of data waveform, local storage of data, data analysis, elementary fault diagnosis and so forth can be achieved all together in a single facility. After tested on the Rotor Kit 4 of Bently Nevada and applied on 300MW turbine of the Power System Dynamic Simulation Laboratory in North China Electric Power University, the newly designed embedded turbine supervisory instruments show that the technique of double CPUs is effective, and the portable system can overcome the deficiencies of the modern embedded turbine supervisory instruments as mentioned above.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.