Applied Mechanics and Materials Vols. 672-674

Abstract: This paper presents the service flow technology based on IEC 61970/61968, and expounds the definition of the service flow and matching method. Service flow technology can support the SOA framework to meet the increasing demand of fusion to electric power information system. An actual service flow case is applied in power information system, the results show that this technology can make better use of IEC 61970/61968 interface, which provide technical methods for the interaction and expansion between information systems.

Abstract: Research on reliability of distribution network has very important meaning and function to ensure the quality of power supply. This paper introduces some basic concepts of reliability in distribution network, including distribution network reliability definition, task and index. The classical reliability evaluation method was reviewed, and focused on specific distribution network, an example analysis was given, and specific reliability evaluation indexes were calculated. Finally, the future development of distribution network reliability evaluation was made a simple prospect.

Abstract: A quenched surface was applied in flow boiling, which is fabricated by quenching a piece of copper in carbon nanotube (CNT) fluid.Its performance was compared with bare copper, and the results showed that the quenched surface can enhance the heat flux by 15–20%. Quenched surface was less effective in enhancing heat flux as the flow rate and liquid subcooling was increased.

Abstract: To obtain evident ion current signals which reflect combustion condition in afterburner, areas of high ion concentration need to be identified. Using C₁₂H₂₃ as the fuel species, H₃O⁺, CHO⁺, COH⁺, O^- and OH^- as main ions, total ion concentration and temperature in flame behind a V-gutter flameholder are numerically simulated by realizable κ-ε turbulent model and non-premixed equilibrium chemistry model. Outlet section temperature is in good agreement with experimental data. The results show that distributions of ion concentration and temperature are consistent. There are two areas of high ion concentration: regions of the highest temperature in recirculation zone; regions close to upper and lower edges of flameholder. Peaks of each area appear near the injection holes.

Abstract: The heat transfer and fluid flow performances of thin film evaporation were investigated numerically in this paper. Based on the coordinate transformation and the Galerkin Method, the analytical solutions of the temperature and pressure distribution within the meniscus bulk region, where the interface is dominated by surface tension were found. The effects of contact angle, superheat and aspect ratio on the temperature distribution of thin film evaporation in the rectangular groove were studied. Meanwhile, the pressure and velocity distribution of thin film evaporation were calculated and analyzed. The results had investigated in this paper can help understanding the mechanism of thin film evaporation for the further study.

Abstract: The codes for ejector nozzle with floating external adjustment sheet were specially developed, the flow field was numerically simulated by using parametric modeling method and grid partitioning technique. Turbulence model was selected according to predictions of explicit algebraic Reynolds stress, specific heat ratio (γ) was based on local temperature and gas compositions. The formulas of ideal nozzle parameters were derived using varied γ, which were used to analyze nozzle aerodynamic performance. The results obtained from constant and variable γ were compared. The results show that: nozzle mass flow rate is reduced because of more difficulty in airflow expansion, while nozzle thrust has a tiny change in variable γ cases. Moreover, the high temperature region of inner nozzle is larger and injected cold air is less despite of a smaller balanced floating sheet angle, which are detrimental to thermal protection.

Abstract: This article is devoted to the complex research method based on mathematical modeling and visualization of thermal fields, which allowed one to obtain the optimal parameters of heat transfer elements of the spacecraft systems of air heating of buildings.

Abstract: As one of the important quality indicators of organic heat carrier, the determination method of Viscosity Parameter has been greatly developed in recent years. In this paper, the traditional and new measurement methods have been summarized and introduced. Then it analyzed the current status and the existing problems of the measurement methods of Viscosity Parameter in our country, and it also prospected the development of the measurement methods of Viscosity Parameter of organic heat carrier. The new measurement method in recent years can be expected to viscosity measurement methods in the field of organic heat carrier along the following direction of development: (1)The traditional measurement methods will be further development and application; (2)The optical measurement techniques will be the most promising method for real-time measurement of viscosity in the organic heat carrier; (3) By using the method of modern data acquisition and processing to improve the traditional organic heat carrier viscosity measurement technology.

Abstract: A calculation method for double-stream counter-current coil-wound heat exchanger is presented for methanol-methanol heat exchange process. The numerical simulation method is applied to determine the basic physical parameters of double-stream spiral pipes. A recycling methanol cooler is designed and calculated by numerical simulation and programmed iterative calculation. The calculation data is analyzed by comparing with different variables. The result shows that the introduction of numerical simulation can simplify the pipe winding process and accelerate the calculation and design of overall configuration. This method can be used for physical modeling and heat transfer calculating of spiral pipes in double-stream coil wound heat exchanger, program to calculate the complex heat transfer changing with different variables and optimize the overall design and calculation process of double-stream spiral pipe bundles.

Abstract: based on previous studies heat storage device structure was optimized and a rectangular tube array encapsulated phase change heat storage device was designed. Compared to sleeve heat accumulator, the heat transfer area was increased 2 times and phase change material thickness was reduced, which has greatly reduced the thermal resistance and improved the heat transfer coefficient. Thermal performance experiment bench of phase change heat storage device was built; heat storage performance experiment was carried on and the results were analysed.