Applied Mechanics and Materials Vol. 483

Abstract: Performance of aerosol sampling inlet for different diffuser outlet angle is compared with its velocity and pressure distribution. To get information on velocity and pressure distribution for different outlet angle, Computational Fluid Dynamic (CFD) simulation can be used. At the same time, it can achieve high efficiency of aerosol sampling and minimize disturbance to the aircraft which carries the system. The final design for the sampling inlet is determined to be a design with diffuser outlet angle of 15 degree. This design was selected to keep stable for velocity and pressure, and have a less length.

Abstract: The spoiler rib is a auxiliary structure of non mesh enclosure soy milk maker, it plays an important role in the process of crushing soybean. In this paper, we designed an orthogonal experiment according to different structure parameter of the spoiler ribs. By using the numerical simulation method, we can get the law of the flow field. We analysised the velocity, turbulence intensity distribution roles in the flow field of different rib's structure parameter, the model of power consumption. Finally, the optimal solutions were found by numerical orthogonal experimental design method in a several turn.

Abstract: In this paper, it was put forward the reversing pulse width adjustment scheme. Precision DSP PWM technology is a good solution to the dead band protection problem, and the piezoelectric feedback link is a good solution to the problem of resonant point temperature drift. Experiments show that the reversing pulse width adjustment method is a good speed regulation method, the dynamic, wide speed range and good linearity governor.

Abstract: This paper introduce three methods for calculating thermal analysis kinetics, and represents the mathematical method Least Mean Square Method to calculate the parameters in the three methods.

Abstract: Wet cooling towers are commonly used in thermal power stations to cool the condenser feed water. The temperature of cooled condenser feed water, which reflects the performance of cooling towers, has a great influence on steam turbine back-pressure and generation efficiency. Merkel Enthalpy Potential Equation is widely used to calculate the temperature of cooled condenser feed water. It is known to all that there is only one true value in nature; however, several solutions according with the equation appears. This paper provides the method to identify the true value of condenser feed water from several solutions, and finally puts forward its iteration calculating method, including the determination of the initial value and stopping rules.

Abstract: An insulation resistance reduction case was studied in this paper. An electrical component composed with metal panel, screw and insulation panel occurred flashover after 2-year service. Environment assessment, dust analysis and material analysis were done to find the reduction reason. The result shows that the reduction is caused by conductive dust aggraded on insulation panel surface; the aged surface of insulation material is favor for the conductive dust aggradation; humid air and high-hygroscopic dust accelerate this aggradation. It is suggested to improve the hydrophobicity and anti-aging property of insulation materials as well as increase the creepage for avoiding the kind of failure.

Abstract: The variable reactor (L) and capacitor capacity (C) of the passive dynamic harmonic filter have influence on the filtering performance. The method of the L and C selecting is advanced in this paper. To select the optimal C, two conditions about the reactive power compensation and harmonic filtering need to satisfy. To analyze L, T-type equivalent circuit is constructed in this paper. With the optimized L and C of the passive dynamic harmonic filter, the harmonic filtering and the reactive power compensation are finished reliably.

Abstract: In view of the industry status that the working performance of domestic bituminous concrete paver is not ideal and corresponding design theory is lack, this paper proposes the compaction system structures of screeding devices, sets up differential equations of vibration system of the freedom degree of the double eccentric block vibration compaction mechanism, sets up the mechanical model of dynamic characteristics of ironing compaction mechanism. With computer simulation, it studies the problems of dynamics of ironing compaction mechanism, analyzes the influence of changes of dynamical parameters of the ironing compaction mechanism on the dynamic characteristics of the system. The study of the dynamic response of ironing compaction systems and dynamic design has important theoretical significance and engineering application value.

Abstract: With gradual increase of requirements for comfort and living environment,braking noise has become one of the issues concerned by people. The research and control to noise has become focus on designing and making braking systems. Based on associated test techniques and analysis theories, the corresponding test, spectrum analysis and coherence analysis are conducted, information about the noise and frequency spectrum is obtained; three-dimensional modeling and finite element calculation are conducted to its constituent components, natural frequency and vibration type figure are obtained. The basis for optimization of brake and reducing noise is provided.

Abstract: Accurate regional wind power forecasting guarantees the security and economics of the power system integrated with large scale of wind power. Aiming at the gross wind power output of the whole regional grid area, existing regional wind power forecasting methods fails to characterize the locally gross output power of the wind farm aggregation forming a power flow interface with specified flow restraints. In this paper, the work flow of the power flow oriented regional wind power forecasting method based on whole-grid regional wind power forecasting methods was presented first. Then, the data preparation, data preprocessing and the mathematical description of the algorithm for our method were presented. Finally, the case study proved the feasibility and effectiveness of our method. The conclusion indicates that the method presented in this paper implements a multiple temporal and spatial scale regional win power forecasting technology, which can obviously improve the accuracy of regional wind power forecasting, relieve the pressure for the grid side and improve the utilization rate of wind power.