Applied Mechanics and Materials Vols. 275-277

Abstract: The properties of particle size distribution of rock cuttings and its shape characteristics are the most important parameters to petroleum drilling engineering. The samples of rock drill-cuttings are collected from 7 wells within the depths of 3500 m in Liaohe Oilfield of China. The particle size distribution laws of these rock samples with the average diameter over 74 μm are analyzed. The result shows that the drill cuttings feature obvious sheet shape and the size distribution curve of the particles is mainly related to the formation rocks and drilling bits. While drilling at the well depths of between 0 and 2000m by the cone bits, particle size distribution of drill cuttings has a form of approximately power function, the probability particle diameter being 8.50～9.27 mm. Drilling at the depths of between 2000 and 2800 m by the cone bits, the size distribution of cuttings has a form of nearly function, the probability particle diameter being 3.04～4.67 mm. Drilling at the depths under 2800m by PDC bits, the size distribution has a form of nearly the Rayleigh distribution, the probability rock diameter being 0.91～0.94 mm.

Abstract: This paper introduces a new and effective study on optimum calculation of the partial ratios of coupled planetary gear sets for getting minimum radial size of the gear sets. In the paper, basing on moment equilibrium condition of a mechanic system including two row planetary gear units and their regular resistance condition, an effective model for determining the partial ratios of coupled planetary gear sets was proposed. Especially, by giving this explicit model, the partial ratios can be calculated accurately and simply.

Abstract: This paper focus on the ship form optimization of a 62-feet yacht and uses experienced method based on amount of statistical data to change the width of knuckle lines in order to reduce the resistance of the hull, including comparison of performance of stability and see keeping.

Abstract: As a heating system of energy saving, environmental protection, comfortable, safe and new-type, low-temperature radiation ground electric heating system has many advantages that other heating ways can not be on a par with such as long service life and free from maintenance within 50 years and has been gradually accepted by broad developers and residents. It has been broadly applied in heat supply in residence, industrial workshop, classrooms and hospitals; warm preservation in pipeline and warming in high tunnel and snow melting in slope road. Take 16 classic users in certain community as research target in analysis of energy saving potentiality of low-temperature radiation electric heat supply.

Abstract: Structural behavior of piezoelectric stacks has a great impact on electromechanical conversion efficiency of highway piezoelectric generators. In this paper, a single piezoelectric ceramic chip in piezoelectric stack structure was regarded as the object of study to construct the ANSYS model of a single piezoelectric ceramic entity. The selection of SOLID5 makes the piezoelectric ceramic chip into the grid cube and by the coupling field, maintains five aspects of static and dynamic piezoelectric coupling characteristic simulation analysis respectively, including static analysis, modal analysis, harmonic analysis, transient analysis and circuit simulation analysis. The results of all the analyses for the optimal structure design of highway piezoelectric generators are to provide a reference.

Abstract: In order to recover the urban sewage energy ,a lab-scale equipment for the sewage energy recovery based on water source heat pump was developed and researched experimentally .The technique of indirect heat exchange by the plastic-Al pipe to recover the urban sewage energy, i.e., the corrosion of the heat exchanger, laying the foundation for the practical utilization of sewage energy. The experimental results show that the developed system is favorable to the environment protection and energy conservation, satisfying the cooling duty requirement with the average coefficient of performance 4.15 in the open cycle system and the average coefficient of performance 3.64 in the close cycle system.

Abstract: In this paper, the analysis of the loading condition and the piezoelectric coupler provides the theoretical basis for the design of the structure of highway piezoelectric generators. Based on the PZT-4, the paper constructs a mechanical model of piezoelectric ceramic stacks. The optimal size of a single chip and the encapsulating form of piezoelectric ceramic stacks are presented with the use of theoretical calculations and ANSYS simulations. The structure of the piezoelectric ceramic stacks is developed to optimize the structure of highway piezoelectric generators and ensure its structure stable and solid.

Abstract: Abstract. At present, many experts are dedicated to applying new control theory in driving system of hybrid electric motorcycles, but the verification of new control theory in real hybrid electric motorcycles faces many difficulties. Therefore, a hardware-in-the-loop simulation platform of hybrid electric motorcycle’s driving system was designed. At first, mathematic model and simulation model of driving motor were designed. Thereafter, the hardware-in-the-loop simulation platform was designed by taking dSPACE as the carrier of simulation model. In view of multiple values and high nonlinearity of driving system in hybrid electric motorcycles, Bang-Bang Fuzzy PID control algorithm was designed. Furthermore, simulation experiments with different control algorithms were carried out through the hardware-in-the-loop simulation platform designed in this paper. Simulation results indicated that the hardware-in-the-loop simulation platform could work effectively and the control effect of Bang-Bang Fuzzy PID control algorithm was good.

Abstract: A dynamic coupling model of the bearingless motor is established. This test does some simulations of motor displacement, no load speed and tracking accuracy under certain performance indicators. Analysis and simulation results show that the system has a control strategy of high precision as well as good dynamic and static performance.

Abstract: In view of the G4-73 type backward centrifugal fan widely used in power plant, training samples for orthogonal test is conducted. A Centrifugal fan performance parameters prediction model based on BP neural network is built. Through the contraction between the predictive value and samples, the accuracy of prediction model is verified. The maximum relative errors of total pressure and efficiency are respectively 0.974% and 0.3327% with the trained neural network to predict on each single test sample, which reaches the predetermined training accuracy, and can be used for fan performance prediction.