Applied Mechanics and Materials Vols. 341-342

Abstract: The modern aircrafts flying height is strictly limited by the conditions on the sea. Terrible conditions may lead overturning or dropping into the water to the aircraft. Whats more, the structure of the aircraft may be broken by water-impact force. The affection of the water impact must be considered to promise the safety of the aircraft. This paper focuses on the water impact to a typical symmetrical aircraft flying above sea. The water impact force related to the trajectory angle and equivalent pitch angle is researched based on the water impact force model of a two-dimensional wedge. In addition, concerning with the limitation of the aircrafts overload, the water-contact condition is proposed to avert attitude overturning and structure broken of the aircraft.

Abstract: The theory, model and algorithm of three products heavy medium cyclone flow field were researched, and the heavy medium cyclone flow field was simulated. Through the researches, the numerical discrete algorithm of heavy medium cyclone flow field was deduced, the calculation algorithms of heavy medium cyclone flow field were given, the flow trace in three products heavy medium cyclone, and the separation rules and flow field characteristics of three products heavy medium cyclone were obtained.

Abstract: The geometry of the tooth surface is important for tooth contact analysis, load tooth contact analysis and the ease-off of gear pairs. This paper presents a mathematical model for the determination of the tooth geometry of Klingelnberg face-hobbed hypoid gears. The formulation for the generation of gear and pinion tooth surfaces and the equations for the tooth surface coordinates are provided in the paper. The surface coordinates and normal vectors are calculated and tooth surfaces and 3D tooth geometries of gear and pinion are obtained. This method may also applied to other face-hobbing gears.

Abstract: The main magnet produces the main magnetic field in the imaging area as one of the important parts of the magnetic resonance imaging (MRI) system. In a permanent MRI magnet, the widespread end effect causes a non-uniform magnetic field distribution and affects the imaging quality. In this paper, an H-type permanent magnet for small-sized MRI applications was designed; in particular, we added an optimized shimming ring outside the pole piece to improve the magnetic field uniformity. Genetic algorithms are used to solve the complex and nonlinear calculation of the magnetic field. The simulation results show that the magnet optimized by the proposed method generates a homogeneous magnetic field that can be easily implemented in practice.

Abstract: This paper studies induced electric fields and current densities for peripheral nerve stimulation (PNS) induced by breast gradient coils. The numerical calculations are based on an efficient, quasi-static, finite-difference (QSFD) scheme. The application of the human body to the calculations of induced current densities and electric fields from applied low frequency magnetic and electric fields is described. The spatial distributions of the induced electric field and their gradients are calculated. This study provides some insight into the spatial characteristics of the induced field gradients for PNS in MRI, which may be used to further evaluate the sites where magnetic stimulation is likely to occur and to optimize gradient coil design.

Abstract: The environmental pollution caused by coal-fired mercury emission has received worldwide attention, because of hazards for human health. Its significant to monitor mercury emission accurately in flue gas for mercury pollution control. In this paper, a detailed description of a mercury continuous emission monitoring system (Hg CEMS) built for the detection of mercury in flue gas is presented. The key performance parameters of the Hg CEMS were discussed in detail. The Hg CEMS was installed in a power plant to monitor mercury emission in flue gas continuously. Results from a series of laboratory performance tests and field application prove that the Hg CEMS is reliable and capable for mercury detection in flue gas. The Hg CEMS can meet the requirement of mercury monitoring in China well.

Abstract: This article proposed a glass flatness detection system. The systems adopt 16 displacement sensors to detect multiple sample points on the glass surface simultaneously. Detection software controls pneumatic devices to realize glass feeding, clamping while displacement sensors detection. Sensors output the detected displacement values in the form of the analog voltage to the data acquisition card. After the A/D cast, the values will be processed and get the thickness, width, flatness and the parallelism value of the glass. Through comparing with predefined limitation to justify whether the product fulfill the requirement. Test result show that proposed system could greatly improve the efficiency and precision of glasses flatness detection.

Abstract: In order to complete the automated sorting, the manipulator needs the accurate coordinate and angle information of the biscuits. This article design a machine vision based online biscuit detection system. Devise the hardware structure and control logic. Base on geometric matching algorithm, develop the detection software with NI Vision. The software could acquire video to analysis to get the coordinates of biscuits, and update and exchange the data with manipulator control software. The system has been tested to achieve a complete detection rate about 96%.

Abstract: Water-entry signal was important to broadcast the water-entry object. The vector sensor could gain the pressure and particle velocity signal, so the azimuth angle of water-entry signal could be estimated by single vector sensor. The complex sound intensity method was applied in vector signal processing in azimuth estimation. The estimated deviation in different SNR was give out via simulating experiment. The method was used in the experiment on the lake and was proved to be effective.

Abstract: Circulating fluidized bed boiler (CFBB) is a distributed parameter, nonlinear, time-varying and multivariate coupling system. Considering these, the core identity of Rough Set and the theory of self-organizing neural fuzzy inference system is applied to the control system of CFBB. The system is carried out toward the 300MW CFBB in Baima Sichuan province, and finally improve the performance of CFBB effectively.