Applied Mechanics and Materials Vol. 376

Abstract: This paper proposes an artificial immune system with a multiplier updating method (AIS-MU) for multiple-fuel-constrained generation scheduling of power systems. The artificial immune system (AIS) equips with a migration can efficiently search and actively explore solutions. The multiplier updating (MU) is introduced to avoid deforming the augmented Lagrange function and resulting in difficulty of solution searching. The proposed method integrates the AIS and the MU that has merits of automatically adjusting the randomly given penalty to a proper value and requiring only a small-size population for the economic dispatch problem (EDP) of the multiple-fuel-constrained generation scheduling. Numerical results indicate that the proposed algorithm is more suitable than previous approaches in the practical economic dispatch of power system.

Abstract: In this paper, the hydraulic characteristics of X-shape flaring gate pier and deflecting stilling basin united energy dissipater are analyzed experimentally on a physical model for large discharge, such as time average impact pressure, close-to-bed velocity in stilling basin and pressure fluctuations. The results show that for large discharge, the deflecting region is the main impact region and the max impact pressure decays with increased water discharge. The close-to-bed velocity decays fast in deflecting stilling basin along the flow direction and for discharge of 14143 m³/s and 17743 m³/s, the max root-mean-square of pressure fluctuation are 2.48 and 2.39 respectively. So the X-shape flaring gate pier and deflecting stilling basin united energy dissipater is a relatively good flood discharge structures combination, which provides strong references for the design of energy dissipater in hydraulic engineering.

Abstract: The interface cracking and fracture behaviors of as-roll-bonded and heat-treated 3-ply Cu/Al/Cu clad metal were investigated Interfacial intermetallic layer were observed to be formed at the Cu/Al interface upon annealing at and above 300°C. The presence of Cu9Al4, CuAl, Cu3Al2 and CuAl2 at the Cu/Al interface was confirmed by XRD. The intermetallic reaction layer has a detrimental effect on the bonding strength of the Cu/Al/Cu clad metal, inducing interface cracks. The length of the delaminated region increased with increasing heat treatment temperature. No strain incompatibility and cracks were observed across the interface in the as roll-bonded clad composite and, for annealed clad composites at 300°C, some appreciable strain incompatibiliy developed, starting to form interface microcracks. For annealed clad composites at 450°C, the interface crack opened wide up with strain because the separated Cu and Al plate deform, developing their independent necks and fracture independently.

Abstract: This experiment represents the effect of impressed current cathodic protection with a variable resistor on concrete specimens. The effect of cathodic protection (CP) system on concrete structures can be changed at different condition. Especially, in marine concrete structures, it is difficult in applying impressed current CP by means of one rectifier in both high resistivity area (dry area) and low resistivity one (wet area). Thus, in this study, the variable resistor was utilized to fulfill similar CP effect on both high resistivity zone and low resistivity one in order to manage the problem. Specimens were concrete slab type with a base of 400mm × 400mm and a height of 70mm. Test factors were CP potential, CP current, and 4-hour depolarization potential. Test results showed that the variable resistor could have positive influences on an improvement in CP effects. In addition, environmental conditions had to be considered to reach enough CP potential and current in this system.

Abstract: The flat plate collector is one of the most widely used device for harnessing solar energy. Measurement of various losses occurring in a flat plate collector is important for design as well as evaluation for efficiency under different conditions. The major part of overall heat loss is the top heat loss. The various losses such as bottom loss, side loss, edge loss, corner loss, sealing loss & top loss etc, are measured as well as recorded. There are forty eight thermocouples located at different points.

Abstract: The paper presents an experimental investigation of using a Molten Carbonate Fuel Cell (MCFC) for reducing CO₂ emission from the flue gas of a lignite boiler. The MCFC is placed in the flue gas stream and separates CO₂ from the cathode side to the anode side. As a result, a mixture of CO₂ and H₂O is obtained; from which pure CO₂ can be obtained by cryogenic condensation of water and carbon dioxide. The main advantages of this solution are: additional electricity generated, reduced CO₂ emissions and higher system efficiency. The results obtained show that the use of an MCFC could reduce CO₂ emissions by 90% with over 30% efficiency in additional power generation.

Abstract: This article describes the function of lightweight visualization tool--Product View. It introduces the application process of lightweight visualization tool--Product View in aircraft development from lightweight model assembly, lightweight model simulation, visual collaboration, collaboration between R & D, and human factor analysis, etc. Product View is a better collaborative communication tool between process design and design, design and technology in the aircraft development.There are not only high demands on the design and assembly, but also a lot of cooperative work between different equipments, equipments and staff, different staff in aircraft development[1]. In order to more efficiently share and use the digital product content created in this process, the demands on high-performance lightweight visualization tool become more and more strongly. Compatibility[2] and interactivity[3] are the two most important indicators when choosing a lightweight visualization tool. Variety of different tools may be used to create digital products during the design process, the compatibility between lightweight visualization tools and digital tools helps to enhance the user’s experience. The interactivity of lightweight visualization tools is also indispensable, it can timely discover the problems of geometric dimensions, tolerance annotations, elements conflict, and interference, give a comprehensive evaluation of the design, and then provide an effective medium between engineering, manufacturing and other downstream participants.

Abstract: The dynamic mesh method that could simulate the actual moving of train was used to calculate the aerodynamic coefficients of train on bridge with wind barriers of various heights, and the static pressure distributions around the train body and velocity magnitude distributions were analyzed, the results computed by dynamic mesh method were compared with that computed by traditional static mesh method. The results show that the aerodynamic coefficients of train and flow field characteristics computed by the two methods agree well under the configuration without wind barriers. However, there is considerable difference between the results computed by the two methods with the installation of wind barriers. It is found that the dynamic mesh method is more reasonable to simulate the aerodynamic coefficients of train with wind barriers by analysis of the contour of static pressure distributions and velocity magnitude distributions. The wind barriers effectively decrease the positive pressure on windward train body and negative pressure on train roof, mainly reduce the side force coefficient, lift force coefficient, rolling moment coefficient. Therefore, the aerodynamic performance of train on bridge under crosswind is improved.

Abstract: Aero-heating problem severely affects the performance of terminal-sensitive projectile (TSP) when projected out of the carrier capsule by the gunpowder gas at a high speed. In this paper, based on the typical ballistic data and airflow physical parameters at deceleration and despinning trajectory, the aerodynamic thermal characteristics of a TSP was simulated by Fluent, and the transient temperature distributions were obtained under the different flying conditions. Finally, we got stagnation temperatures by the numerical simulations which were similar to those by the engineering evaluation, and demonstrate the effectiveness of the simulation method. The results are valuable to the research of thermal protection and infrared signature of TSP.

Abstract: With the development of the technology of workflow management, the way of working in companies has been changed a lot. However, the traditional technology of workflow could only deal with the same type of instances. Aiming at solving the problem of collaborative work when there are multi-tasks between cross-departments, we propose an approach of modeling the task distribution process between cross-departments based on colored Petri nets. Firstly, the concept of colored Petri nets and some related characteristics are discussed. Then this method is applied to model the distribution process of CAD-CAE collaborative task. A model of CAD-CAE collaboration is given. Finally, the deadlock of the model is found and the solution is proposed.