Applied Mechanics and Materials Vols. 457-458

Abstract: This study presents the optimization of the geometry of pin-fin heat sink with un-uniform fin dimensions. A procedure is presented to find the optimum geometry of pin-fin with un-uniform fin heights and widths. It is concluded that the highest temperature is lower and the temperature gradient is smaller in the optimum geometry, and the fin heights and widths near the central part of the heat sink are higher and wider than the fins at the edge. As the total volume of fins increases, the entropy generation decreases while the decreasing rate slows down.

Abstract: because of the existence of non-linear loads,they will be inpouring a lot of harmonic current to the power system,in order to restrain harmonic,we have to take relevant measures to restrain. This paper introduces three measures of harmonic restraint firstly, expounds the active power filter, and then it analyses the work principle and mathematical model of shunt active power filter , building three-phase shunt active power filter simulation model,; At last, using MATLAB simulation experiment ,the result shows that the shunt active power filter of harmonic detection algorithm and the control strategy are correct and effective , and also it has the important significance to the power system harmonic restraint.

Abstract: This paper presents a framework of prototype compressor impeller auto-test system. Two type performance test can be held in a unique pipeline layout. Work conditions are accuratly under control. Status data is acquired synchronously and precisely. Performance evaluation is accomplished efficient. This framework is proved to be highly available to improve traditional manual test method.

Abstract: Combined with the advantages of good protection of global robot, self-equilibrium, easy control of wheeled robot and strong obstacle surmounting ability of turbofan robot, a variable structure mobile robot which has three kinds of basic modalities of global, turbofan and three-wheel is designed. The balancing leg is retracted and the two polymorphic wheels of the robot are closed into a sphere while in the global state, and it could be conveniently threw, carried and make all directional movements on the flat grounds. When confronted with the complicated terrain environments of sand, slopes etc., the two polymorphic wheels will be outspread to the turbofan state, and the balancing leg will be opened out as a third supporting wheel so as to strengthen the ability to adapt to the environment. When the two polymorphic wheels are expanded into two wheels, the robot motions are more smoothly and easily to be controlled. A virtual prototype of the robot is designed by three-dimensional technology, as well as the motion simulation. Rationality of the mechanism design scheme of the variable structure mobile robot is verified.

Abstract: Although pressure compensating emitters (PCE) have many advantages, they are difficult to develop and very costly. Traditional PCE are composed of emitter structures and compensating diaphragms. Their manufacture is very difficult and time-consuming. In this paper, we invented novel PCE with variable flow channels, which are designed as integrated structures with pressure compensating barriers, and manufactured three of them with different structures based on the rapid prototyping/rapid tooling technology. The pressure-flow test showed their behavior indexes were 0.009, 0.008 and 0.011, respectively, indicating this type of novel PCE have remarkable compensating effect.

Abstract: CRT- 83 carpet rapier loom is a kind of high-grade rigid rapier loom，the weft yarn will give looms to demand higher stability of the weft insertion. Theoretical analysis based on the theory research of the stability of clamping weft and weft handover shows that the rapier deformation，slipping force and the depth of clamping are main factors influencing the stability of weft insertion.In order to obtain reasonable process of weft insertion，concerned with the following factors：the grip length and outrigger length of rapier，release times of clip yarn device，initial deformation angle of spring piece.

Abstract: The characteristics of traction motor for electric vehicle is introduced here. The qualitative analysis on the relation between the base speed ratio and power is showed. The emphasis is on the analysis and comparison for permanent magnet brushless DC motor, induction motor and switched reluctance motor.

Abstract: Horizontal well technology has become an important technological means for offshore oilfield exploitation, but at present, most of the fracture parameters optimization of horizontal well fracturing are based on the single wells productivity after fracturing and pay less attention to consider the impact of injection wells.Therefore, aiming at injection and production development mode of BZ oilfield horizontal wells after fracturing, Integral fracturing physical model and productivity forecast mathematical model of horizontal well for the purpose of improving integrated exploitation benefit of the block is established respectively.Combining with reservoir parameters of BZ oilfield, a corresponding numerical simulator is developed by means of solving mathematical model to forecast production performance of oil well with different fracture number, fracture length, fracture conductivity. The best fracture parameters are obtained through analyzing the effect of fracture parameters on accumulative oil production, which provides theoretical foundation for integral fracturing optimization design of horizontal well of BZ oilfields, and has vital site guiding significance.

Abstract: Metal structures of present port machineries are much more flexible than those decades ago, and are therefore very vulnerable to various wind-induced vibrations, among which the frequently happened random buffeting of structures attracts some special attentions since it contributes pretty much to the early structural fatigue. The intensity of buffeting is closely related to the local surrounding wind field. In this paper, the local wind field of a container port in Shanghai of China was simulated by CFD technique, and the corresponding spatial distribution of wind velocity, turbulence intensity, and wind profile were investigated in detail.

Abstract: The acoustic performance of sound-isolating and decoupled tiles is studied from macroscopic and microscopic. First, the sound absorption and reverse sound insulation performance of sound-isolating and decoupled tiles is studied based on laminated media; then the acoustic decoupling materials influence on acoustic radiation of double cylindrical shell underwater is studied, using a double-layer cylindrical structure of large-scale as experimental model .There are large amount of operating modes designed in this experiment, such as all laying, partial laying, laying and so on. The results show that sound-isolating and decoupled tiles not only have the effect of weakening the absorption of reflections, but also have reverse sound insulation effect, which increases as frequency increases; for single point mechanical vibration, the tiles can effectively inhibit vibration and sound radiation of high frequency in the double shell.