Applied Mechanics and Materials Vol. 472

Abstract: The deposition of paraffin wax during the pipeline transportation impedes the flow of crude oil and eventually blocks the pipelines. In recent years, electromagnetic paraffin control technology was increasingly utilized as an alternative energy-saving method. However, the efficiency of magnetic paraffin control is restrained by edge effects in conventional anti-wax apparatus. So, theoretical and experimental researches on novel anti-wax apparatus with step solenoid have been performed to improve the efficiency of paraffin control. The effect of geometric structure on field distribution was investigated to optimize the coil structure using finite element simulations. The effective correction of the edge effect of conventional solenoid field and the elimination of novel edge effect induced by the step field manifest the superiority of multi-step coil structure in paraffin control. Therefore, a novel apparatus with positively multi-step structure in the outlet of the excitation solenoid and negatively multi-step structure in the inlet was presented.

Abstract: To improve the dynamic response and of compensation characteristic three-phase shunt active power filter(APF),a novel control strategy was proposed based on supply voltage detection. Fundamental wave current controller and dc side voltage controller was designed in detail. This method can not only compensate the parameter is determined and position distortion load, also can compensate the uncertain load.The superiority of the control architecture proposed is verified completely by simulation results.

Abstract: Cooling module simulation for vehicle has been built according to the heat balance test, and the simulation results are compared with the test data to verify the authenticity of the module. This simulation model provides an effective platform for vehicle thermal management analysis. Module is used to simulate the air conditioning running and to find how different ambient temperaturesto effect the performance of the cooling module. The air conditioning working and ambience temperaturewhichis significantly influence the performance of the cooling system.

Abstract: Cascading trips caused by flow transferring are the crucial reason for a lot of well-known blackouts. Aiming at the distance relay which is most applied in power grid, this paper puts forward an adaptive setting scheme to prevent cascading trips in complex power grid. In this paper, using two-port network model to fast calculating apparent impedance, and than calculating the apparent impedance change rate which is caused by flow transferring. According to the apparent impedance change rate modify the setting value which would contract the range of the impedance circle. After accomplishing the contraction, the relay action check will start. Through the process of modification and checking, the adaptive setting scheme which is not affected by the flow transferring will be formed. Taking the New England 10-unit 39-bus system which also used this method as the example, in this case, this method is confirmed by the BPA simulation.

Abstract: A Switched Reluctance Motor and Generator (SRMG) has a simple double salient pole structure that uses reluctance torque and does not use a permanent magnet, making the unit price low. This kind of structure makes it mechanically tough, have outstanding output characteristics making it used as traction purpose. However the noise, vibration and torque ripple is bigger than other motors and because it does not have any magnetic flux in the rotor, it is not useful in regenerating.[[ In this paper, novel regenerating method with separate excitation driving technique is presented. It is different from the existing regenerating brake that uses the remnant flux on a separate excitation type by using a parallel switching base to redirect portion of the flux path to excitation and the rest to generation. The proposed method makes it able to use a larger portion in generating, there is no limitation in the excitation current in order to generate and the control of the output is simple. Because the proposed method is based on the parallel switching technique the number of switch per phase does increase. However in motor mode the division of current goes down making it easier to go in generating mode. The proposed method is generated upper 50% regenerating power rate more than general method. In order to prove the possibility, a simulation of flux flow using FEM is applied. The proposed method is also verified by experiment result.

Abstract: Based on the method FW-H acoustic model, how the parameters influence acoustic characteristics of the Hartmann acoustic generator were studied, which are resonator length, spacing between the jet and resonator tube, the diameter of resonator tube. The conclusions were induced just as below. The total sound pressure level (SPL) increases with the length of resonator tube, while the magnitude of fundamental frequency is reverse. And the total SPL oscillates with the increase of spacing between jet and resonator, and the oscillating distance period increases with diameter of resonator tube. And the Hartmann generator with larger diameter of resonator tube can produce a higher SPL. The results of the paper provide the instructing meaning for the application of the Hartmann acoustic generator.

Abstract: Interfenrence detection is a crucial problem in the process of the stationary internal toroidal gear machining. This paper proposes a new method to detect interference regions in 3-axis stationary internal toroidal gear machining. With this method,numerical control machining geometric model is built to detect interference. Interference regions can be identified effectively by comparing intersection point between detecting line and spiral tooth flank with that between detecting line and tool sweep. It was found that this method not only can be used to detect local interference regions but also global interference regions according to whether dectecting line and not processing area of curved surface have intersection point.

Abstract: A micro-fluid turbine with mechanical energy storage system is designed and successfully tested in laboratory. As energy supplement for deep ocean installations, this patent design solved the problem of difficult generating electricity in ultra-low speed flow. The conventional marine current turbine can hardly get start in flows with velocity lower than 0.5m/s, whereas the marine current speed is seldom higher than one knot in deep sea. By adding a mechanical energy storage system, the rotor of the micro-fluid turbine first captures the fluid kinetic energy from the ultra-low speed flow, and then the energy transferred to the mechanical energy storage system, in which a plane scroll spring is used to store the limited energy and drive the generator automatically when it has enough potential energy. Simulation and laboratory test show that this method has potential for power generating in low density ocean current environment.

Abstract: The growing demand for accurate performance simulations of high-power Li-ion traction batteries requires a fast and effective method. In this paper, an advanced estimation model is proposed to evaluate Li-ion traction battery performance in pure electric vehicle (PEV) applications. The estimation model, which combines road load simulation and lumped parameter analysis, can predict vehicle traction power requirements and entire battery performance parameters both for charge (regenerative braking or grid charging) and discharge (traction power) processes. The model is validated for a battery pack in a PEV operating over three representative driving cycles: (i) the new European driving cycle (NEDC), (ii) 60km/h constant speed driving cycle, and (iii) 30min maximum speed driving cycle. The results show that the combined performance model output corresponds well with measured data. Thus, this new proposed model can be used to validate battery pack performance during in-vehicle use with reasonable accuracy.

Abstract: Control system is generally verified by experiment, some of which are too difficult or high-cost to implement, while physical simulation can be substituted for experiment to verify the effectiveness of control system. The study take the heat exchanger as an example to describe the process of verification by physical simulation: Choose FLOEFD and SIMULINK as the software of physical simulation and control system design, establish the mathematical model of heat exchanger, design control module, whose output is set as an input of FLOEFD, compare the result of physical simulation and SIMULINK, if they are similar, the control module is effective.