Papers by Author: Ming Yu

Abstract: In order to keep gas turbine disk safe and reliable, and to provide reliable data for the dynamic design or modification of a gas turbine disk, dynamic characteristic of the gas turbine disk has to be obtained. In the paper, the method based on the combination of calculation mode and the experiment mode is proposed to analysis the dynamic characteristic of the gas turbine disk. The modal parameters and the mode shapes are calculated through ANSYS program. On the basis of these modal parameters, the faults of the gas turbine disk are shown and its weak points of the design are illustrated. The reason for deformation is analyzed and relevant measures employed to reduce faults are proposed. By these improvements in question, a guarantee of the gas turbine disk working normally has been available.

Abstract: In order to provide high precise data for urban natural gas pipeline network dynamic modification and to diagnose the urban natural gas pipeline network fault, the dynamic characteristic of the flow-meter system, which is the main component of a natural gas pipeline network, has to be obtained precisely. The experimental modal parameters identification method base on the modal theories is proposed to substitute for the finite element method to identify the modal parameters of the flow-meter System. Multiple-point exciting by a hammer and single-point collecting by acceleration sensor can obtain testing data of the flow-meter System. The initial frequency and damping ratio of the flow-meter System can be distinguished out base on the testing impulse respond functions data. According to these modal parameters, the reasons of its faults under a certain working condition can be analyzed specifically. Simultaneously, the accuracy and reliability of this parameter identification method can be inspected on experiment.

Abstract: Vibration and radiated sound of Air Conditioning are harmful to environment and safeness. Air Conditioning Compressor is its major part bringing vibration. To lower noise of a compressor and to improve its sound characteristic, the paper probes into a method indirect measurement of vibration, which both vibration and radiation behavior is represented using acoustic signal and theory of radiation modes. The paper investigates on the basic coupling relationship between structural vibration and acoustic radiation by means of the real modal analysis theory. Besides, the vibration and acoustic radiation characteristics of the rotary compressor are identified through the experiment method. According to the experimental results, between the vibration modes and the acoustic radiation modes have the comparability about the parameters. Therefore, this paper put forward a new method to the Active Structural Acoustic Control (ASAC), and provides the theoretical foundation of indirect measurement of vibration by using acoustic signal.