Applied Mechanics and Materials Vols. 401-403

Abstract: The paper establishes a three-dimensional solid model of the frame, and simplifies the frame model according to the simplification rules of finite element. Use Pro/MECHANICA module of Pro/ENGINEER software to carry out static and modal analysis of the frame, and to conduct sensitivity analysis of geometric parameters having a great impact on the frame characteristics, thus the most sensitive size parameters of the frame performance are gotten. By optimization design function of Pro/MECHANICA module, specifying goals of optimized design and ranges of size sensitive parameters, the frame structure is optimized.

Abstract: The use of air cavities beneath ship hulls can lead to significant drag reduction. A study of air-ventilated cavities under a traffic vessel with flat bottom has been undertaken based on solving the RANS equations and VOF multiphase model. Macroscopic features in the air-cavity flow are predicted. Why the existing cavity form leads to unsatisfactory results on the traffic vessel is analyzed. The influence of parameters of artificial cavity on air cavity patterns is parametrically studied. Suggestions on improving cavity parameters and a new cavity form that can obtain stable air cavity are given, which may provide reference for the design of air cavity traffic vessels.

Abstract: In order to study the high temperature heat harm problem in the process of deep mining, Briefly analyzed the causes of high temperature by using the methods of theoretical analysis and field measurement. In addition, a series of high temperature control methods are put forward. Including take conventional non-artificial cooling and the artificial refrigeration cooling methods as well as new cooling methods of using geothermal energy cooling and combined cooling heating and power technology so many initiatives to solve the problems of high temperature of deep mine. The engineering practice proves the reliability of mine cooling technology,the results can provide a basis for prediction and control of high temperature of deep mine.

Abstract: Ball type joint is one of key component of automotive drive shaft, which is used in a front drive transmission vehicle for transmitting rotary movement from the gearbox output shaft to the wheels with a constant velocity. It has been found that the ball type joint is usually failure caused by abrasive wear. This paper is dedicated to analyze the abrasive wear by theoretical investigation on the relatively slipping velocity of each component of the ball joint, as well as the experimental approach. The results show that the grading of abrasive wear of the components is largely depended on the relatively slipping velocity.

Abstract: The size of bore diameter of hollow screw, to some extent, will affect the dual-drive feed system's static stiffness, and then affect the machining accuracy of the workpiece. This paper takes the dual-drive feed system as the research object and builds its finite element model. Use the model to make static analysis in Workbench. After that, we can get the relation between bore diameter of hollow screw and static deformation of the dual-drive system. The results demonstrate that: with the bore diameter of hollow screw increases, the maximum static deformation volume of the dual-drive system gradually becomes larger. This article suggests that the appropriate design size of the diameter should be 4~10 mm. Because the corresponding static deformation of the dual-drive system changes little in magnitude within this range. These advised parameters can provide certain principles for the improvements of a hollow screw shape and size and its parametric design.

Abstract: Two air jet curtains can enhance the ability of tunnel air control, but the interactional influence between two jet bring side-effect at the same time, this side effect changes with jet flow, space size, which may harm the ability of tunnel air control in disadvantage situation. This article use FDS to simulate flow pattern of two air jet in different situation, get stability condition and air control ability in different jet situation which can provide guidance for air jet, air control engineering.

Abstract: Design of tennis transmitter design parameters, structure design, choice of institution, etc., the transmitter in accordance with the standards of the international tennis federation (ITF) to carry on the design. Design and institutional selection includes the realization of the crank connecting rod mechanism and control motor sports, ball tray and ball under the control of the speed of tennis, crowded ball wheel speed regulating motor selection, crowded round ball structure design and checking calculation, the design and checking calculation of shaft, casing and bracket material design and the selection, selection of walking wheel, etc.

Abstract: The boot method of three wound-rotor asynchronous motors and three-phase squirrel-cage asynchronous motor are described; As to reduce the start current and to increase the starting torque, the principle of all kinds of startup methods are analyzed; the advantages and disadvantages of various starting methods are evaluated; Development directions of modern motor startup are pointed out.

Abstract: The text introduces the structure of steam turbine-driven feed water pump briefly, analyzes the difference between steam turbine-driven feed water pump and electrically driven feed pump, and expresses the working principle of centrifugal pump. Besides, it researchs the advantage of raising head of multistage pump by the analysis of a three-level feed pump, states that pump power loss can be divided into mechanical loss, flow loss and volumetric loss respectively and sets up the mathematic model with the power and efficiency and concludes the calculation method of the overall efficiency of multistage pump and analyzes the relationship between the various power losses and rotational speed and presents specific measures to improve the efficiency.

Abstract: This paper is based on the kinetic theory of ore and steel balls in the SAG Mill and theoretical research of power consumption. Orthogonal method is taken to design experimental plan while effective power of the SAG Mill, collision times between steel balls and the SAG Mill and collision times between steel balls and ore are designed as optimal objectives. Model with 9 experimental points is simulated by EDEM and experimental data are disposed Range Method in order to get the optimal combination of operating parameters of the SAG Mill.