Advanced Materials Research Vols. 383-390

Abstract: The radial temperature difference calculation of a steam drum shell is an important step in the process of calcu-lating its heat stress, so the current Chinese Standard recommended a computing method which was derived from the further modification to the simplified solution for the radial temperature of a steam drum shell. In order to derive the feasibility for the application of the current Chinese Standard computing method to a supercharged boiler, the computing method for the temperature difference of a steam drum shell, which was based on the approximate solution for the radial temperature of a steam drum shell and highly approaches to its analytic solution, was exercised. By analysing the computed results of examples, the conclusions show as follows: The current Chinese Standard computing method for the radial temperature difference of a steam drum shell can’t meet the calculation requirements of all the running work conditions and their courses of a supercharged boiler, and as a universal computing method, it can’t serve as a computing method for the same problem of a supercharged boiler. Whereas the approximate solution can apply to calculating the same problem of a supercharged boiler and a peak shaving utility boiler. Thereby the basis is offered for the selection and usage of the computing method for the radial temperature difference of a supercharged boiler steam drum shell, the pioneering researches on its interrelated problems and prac-tical applications.

Abstract: As life-saving facilities for individual and family in current domestic market is almost blank, this paper, using the theory of man-machine engineering, makes human, machine and environment as a whole to give a comprehensive analysis among flood audience, rescue production and environment. According to the audience’s physiological and psychological demand, it puts forward the concept of flood survival kit. With detailed description of its content, material, color and size, the paper provides a more humanized point for the design of flood survival kit.

Abstract: Novel phthalocyanine derivative and azo derivative have been synthesized as photosensitizers for the dye-sensitized solar cells (DSSCs). We used sol-gel method to prepare the titanium oxide (TiO2) membrane electrode of the DSSCs. The crystalline phase and surface morphology of TiO2 were characterized by using X-ray diffraction (XRD), and field emission scanning electron microscopy (FE-SEM) to investigate the effects of processing parameters on the films characteristic, microstructure and thickness. The performance of DSSCs was characterized by using electrochemical impedance spectroscopy (EIS) and current-voltage curve analysis. The sensitizing properties of phthalocyanine derivative, azo derivative and mixed dyes were studied, and it was found that the cell consisted of mixed dyes generated the highest power conversion efficiency () of 2.3 %, short circuit photocurrent density (Jsc) of 13.6 mA cm-2, open circuit photovoltage (Voc) of 0.46 V and fill factor (FF) of 0.37 under simulated AM 1.5 irradiation (100 mW cm-2) with a active area of 0.25 cm2.

Abstract: The main objective of this paper is to investigate the suitability of Soft Magnetic Composite (SMC) material SOMOLOY1000 for a Switched Reluctance Generator (SRG) through electromagnetic, thermal and vibration characteristics employing extensive Finite Element Analysis. The fabrication aspects of Soft Magnetic Composite Switched Reluctance Generator (SMC-SRG) using preform material blanks utilizing indigenous machining process have been delineated. The static and transient electromagnetic characteristics have been obtained through the electromagnetic finite element analysis software MagNet6.22.1 while the thermal and vibration aspects have been studied through coupled field Finite Element Analysis employing the multi physics software ANSYS10 while the Impulse hammers excitation - free vibration test using RT Pro Photon data acquisition system facilitated the experimental determination of vibration characteristics. The study concludes that the advantages of less weight , low torque ripple, low eddy current losses, reduction in vibration level of stator structure coupled with the ability to maintain precise mechanical dimensional tolerance may present SMC-SRG a viable candidate in standalone wind energy conversion systems meant for rural and remote area electrification scheme.

Abstract: Uniform parallel pores and controllable pore diameter make Anodic Aluminum Oxide (AAO) membrane one of the best materials in synthesis of one-dimensional nano-structured material. High orderly AAO template was prepared by anodic-oxidation. The prepared AAO membrane’s apertures ranged from 30 nm to 75 nm. Within a few microns, holes were orderly arranged. The fabricating methods of AAO template in different electrolyte were studied and the factors which affect the pore distribution, such as electrolyte types, voltage and concentration were discussed.

Abstract: PM (Permanent Magnet) biased magnetic bearing with PM to replace the magnetic field produced by electromagnet an Active Magnetic Bearing generated static bias magnetic field, it can reduce the power consumption of power amplifier to reduce the number of turns of magnet safety, reduce the volume of magnetic bearings, reducing electromagnetic coil operating current, thereby reducing the power amplifier power control system and heat sink size, magnetic bearings significantly reduce power loss, and fundamentally reduce the cost of bearing. In this paper, a kind of PM biased magnetic bearings, describes its structure and working principle, derived a mathematical model of magnetic bearing and magnetic circuit of PM biased magnetic bearings are calculated, given the specific PM biased magnetic bearing size and accordingly calculate the parameters of magnetic bearings. A magnetic model constructed using Simulink simulation method, and constructed using this method, magnetic bearing specific mathematical model simulation results show that the rotor position in the balance, X and Y decoupling between the control winding, while the deviation from equilibrium position time, X and Y control coupling between the windings, the simulation results and the calculation results.

Abstract: An entropy generation analysis method based on the second law of thermodynamics was used to component level optimization design of aircraft environmental control system in this paper. Through analyzing the air flow process in environmental control system, the function relationship between system entropy generation and present initial conditions was achieved. Along with the heat exchanger design calculation process, as the bleed air pressure and cabin design temperature change, the effect of the ratio between the heat exchanger heat side flow length, cold side flow length and height on whole system entropy generation was obtained. The results obtained in this paper have some guidance function on aircraft environmental control system optimum design.

Abstract: A nonlinear optimal controller for excitation control of synchronous generators is presented. Based on differential geometry theory, the controller is designed by transforming the nonlinear system to an equivalent linear system. The analysis and simulation of a single-machine infinite-bus power system indicate that the stability of the proposed controller better than the stability of conventional linear controllers

Abstract: In reentry flight phase of reusable launch vehicle (RLV), its aerodynamic characters alter sharply, going with serious uncertainties and nonlinearities. These factors make the reentry attitude control technique be one of key technique for RLV. In this paper, the sliding mode variable structure control technique is used for reentry attitude control. A specific switch function is defined; a specific exponential reaching law and continuous analogy of sign function are chosen to weaken the chattering brought by the variable structure control technique. RLV is equipped with aerosurfaces and reaction control system (RCS), the arithmetic based on dynamic pressure change is presented. Six-freedom nonlinear simulation with great gain and high frequency disturbance proves that the reentry attitude control technique performs very well, and its control accuracy and robustness are brilliant.

Abstract: The gas turbine blade was studied on the condition that the mainstream velocity was 10m/s and the Renolds number based on the chord length of the blade was 160000.The Hot-film anemometer was used to measure the two-dimension speed distribution along the downstream of the film cooling holes on the suction side and the pressure side. The conclusions are as follows: When the blowing ratio of the suction side and the pressure side increasing, the the mainstream and the jet injection mixing center raising. Entrainment flow occurs at the position where the blade surface with great curvature gradient, simultaneously the mixing flow has a wicked adhere to the wall. The velocity gradient of the u direction that on the suction side increase obviously, also the level of the wall adherence is better than the pressure side. With the x/d increasing, the velocity u that on the pressure side gradually become irregularly, also the secondary flow emerged near the wall region where the curvature is great. The blowing ratio on the suction side has a little influence on velocity v than that on the pressure side.