Applied Mechanics and Materials Vols. 271-272

Abstract: Wing aircraft is one of the major components to generate lift, in today's energy shortage, design the high lift-to-drag ratio wing is the goal pursued by, The author in the exploration of bionic airfoil aerodynamic characteristics on the basis of, which will be applied to straight wing design so as to improve the aerodynamic performance of aircraft.Our research mainly includes two aspects: first, the use of imitation seagull airfoil and NACA4412 airfoil are designed into the straight wing. The use of FLUENT software in Re=300000condition carries on the numerical simulation results show that the ratio of gull wing airfoil than NACA4412 lift coefficient increased by 13%, while the lift to drag ratio,is improved by 46.83%. Then, using the similarity principle, the wing scale, was tested in a wind tunnel test, the results obtained with the simulation are consistent. Airfoil design for the design of high performance wing opened a new way.

Abstract: In order to study conveying roller force and improve its mechanical properties, we use three-dimensional modeling software Pro/E to build the solid model of the Apple box delivery device’s conveying roller. Using finite element analysis software Ansys to analyze conveying roller’s bending stress, we can get images of local strain and displacement contours .Contrasting with factory’s broken roller conveyor, we can find that: through the establishment of appropriate boundary conditions, Ansys can accurate finite element analysis, and provide the basis for the conveying roller structure improvements.

Abstract: This paper aims to investigate the cell layout problem of aircraft assembly system. A mathematical model for this problem is proposed, taking into account the integration design of cell layout and logistics network. The means of logistics transportation are divided into horizontal transportation and space transportation, meanwhile, the logistics transportation route is calculated. Based on sequence pair, the presentation of solution structure for cell layout is put forward, and the solution structure is solved using simulated annealing algorithm. This method is applied successfully to the assembly cell layout of the fuselage-wing assembly system for a giant aircraft, and the result shows its feasibility and effectiveness.

Abstract: This paper gives the definitions of exported design and residual design is given. The relation of order between derived design and residual design has been clarified. The blocks capacity in derived design are and the blocks capacity in residual design are . The number of non-isomorphism derived design is equal to the residual design. If the incidience matrix of derived design is , then the incidience matrix of residual design is . The blocks in derived design and the blocks in residual design exist the complementary relationship. The construction methods of derived design and residual design have been proposed. The entire procedure of constructing (15,7,3) derived design and (15,8,2) residual design is also presented completely.

Abstract: The paper analyzes existing problems in China's freight car color coating, compares the gap between same products abroad, comprehensively analyzes relevant factors which affect freight car coating, uses system theory combined with specification of safe color, visual safety psychology and coating material technology and takes requirements such as type, structure, safety and corporate image into consideration to establish China's railway freight car color coating genealogy. It provides systematical advices for China's railway freight car color coating design and solves problems like single and disorder coating color, poor indicative of safety feature to improve the level of China's railway freight car coating design.

Abstract: A planetary gear train consists of a sun gear, planet gears, and a ring gear and these gears are arranged as a concentric circle type. The gearbox proposed in this study arranges the planetary gear type as a double planetary gear train in which the output of the primary gear train is used as an input to the secondary planetary gear for accelerating its speed. In this design, a method that directly connects the input and output sections is introduced to obtain a high acceleration ratio and its applicability is verified for applying it to a small wind turbine through designing and fabricating the planetary gearbox.

Abstract: In this paper, endoscope with aided lens was designed for observation of fire-fighting foam. Firstly, water-proof and corrosion-resistant endoscope was completed according to the foam’s characteristics. Then, aided lens for clear observation was designed corresponding to the endoscope’s lens system. Secondly, the fire-fighting foam was produced using low expansion foam extinguishing system and observed through endoscope with aided lens. Finally, the data were analyzed considering the foam’s drainage process. This endoscope with aided lens could be used to describe foam’s interior structure’s evolution including foam drainage, film rupture and bubble coarsening.

Abstract: Because of its advantageous aerodynamic performance, the vertical-axis wind turbine (VAWT) has gained more and more attention. This paper studies the vibration characteristic of the VAWT main spindle, and presents a mechanical and electromechanical coordination vibration suppression method for the VAWT main spindle. The proposed method can measure main spindle current vibration intensity in real-time. And when the main spindle vibration intensity exceeds preset critical control threshold value, the method can use both the on-line intelligent analysis decision and the mechanical and electromechanical coordinated controller to suppress the main spindle vibration, as well as to make the VAWT maintain mechanical stability. At the same time, the method can ensure the VAWT meets maximum wind energy capture efficiency as far as possible.

Abstract: Configuration design on an impeller using to the centrifugal compressor of turbocharger was conducted to improve its performance. Impeller shape was adjusted by changing its meridional contours and blade profile. Total nine design variables were chosen with constraints. ANN (Artificial Neural Net) was adopted as a main optimization algorithm with PSO (Particle Swarm Optimization) in order to reduce the optimization time. This ANN was learned and trained with the design variable sets which were obtained using DOE (Design of Experiment). This ANN was continuously improved its accuracy for each generation of which population was one hundred. New design variable set in each generation was selected using a non-gradient based method of PSO in order to obtain the global optimized result. After 7th generation, the difference of efficiency and pressure ratio predicted by ANN and CFD (Computational Fluid Dynamics) was less than 0.6%. From more than 1,200 design variable sets, a pareto of efficiency versus pressure ratio was obtained and an optimized result was selected based on the multi-objective function. On this optimized impeller, the efficiency and pressure ratio were improved by 1% and 9.3%, respectively.

Abstract: New-type hypersonic vehicle will encounter significant challenges due to severe heating environments during its long-time hypersonic flying in the atmosphere. Therefore, resusable, lightweight, high thermal resistance and anti-collision are demanded for Thermal Protection System. Traditional thermal protection system(TPS) can’t survive extreme thermal environments. In this paper, lightweight and integrated graded hot structures which composed of functionally graded materials (FGM) are addressed according to new thermal environment. It has been established nonlinear fundamental equations for hot structures. It is significant that gradation in material properties of hot structures allows the designer to tailor thermal response to meet variable thermal environment.