Applied Mechanics and Materials Vol. 711

Abstract: Tubular hydropower station is a better way in the development of low-head hydraulic power resources. More and more people begin to study the tubular turbine in depth with the development of hydraulic power recourses in the direction of low head and large capacity. With the unique structural features and adaptive head range of tubular turbine, its development is very fast in recent years. The strength analysis of a tubular turbine is an important research aspect with the increasing of its capacity. Bulb turbine is one of the main types of tubular turbines. This paper uses CATIA software and finite element analysis to analyze and calculate the strength and deformation of key components of a bulb turbine, so as to ensure the bulb turbine's safe and reliable operation.

Abstract: With the economic development,the transport capacity of the existing transmission lines can not satisfy the demand for electricity. When the line needs expansion we propose to replace the new optional wire to reach the goal line expansion without changing the existing transmission line structures premise of the original line. We should consider energy conservation, temperature, security when running on N-1 and sag expansion to the main line. To satisfy these requirements, we set up the principle of development for the proper ties of the conductors to be developed and made assessment on the newly –developed conductors in China and foreign countries in recent years.

Abstract: An experimental investigation was completed with the objective of determining the performance characteristics of propeller in a Ducted-Fan Type VTOL UAV. The model consisted of three groups of two-bladed propellers with or withou an annular duct. The propellers share the same diameter but differernt blade pitchs.Model variations included the changes of the propeller and the duct shrouded combination. Static propulsion test data showed figure of lift increases with increasing blade pitch. The coaxial propellers lift did not perform as 2 times of the single propeller lift.The duct increase the duct fan system lift effectively.

Abstract: . This paper studies the different diameters of tube outlet how to affect the gas flow pressure and velocity distribution in nanofiber catalytic converter by CFD (Computational Fluid Dynamics) method. Geometric model of the catalytic converter has been established and meshed by the pre-processing tool of FLUENT. The distribution of velocity and pressure in the converter which outlet diameter is 70 mm is more evenly than the converter which outlet diameter is 50 mm. It is conducive to reducing airflow static pressure in the catalytic converter that expanding the outlet diameter in the case of other conditions remains unchanged. Therefore, the larger outlet diameter is beneficial to exhaust catalytic reaction.

Abstract: The influence of the radiator and other components in the noise prediction process of cooling module is difficult to calculate. Firstly, the model including porous media is established. And the large eddy simulation (LES) is used to analyze its impact on the inflow instability and calculate the urbulent kinetic energy and vorticity around the fan. Then the main noise sources are identified by vortex sound theory. The acoustic BEM model is established for discrete and broadband aerodynamic noise prediction of cooling module. And the sound field sound pressure spectrum is analyzed. Finally, the noise test is made to verify the prediction. The results show that the radiator and other components have a huge influence in the flow field and noise prediction and they can not be ignored in the aerodynamic noise calculation process.

Abstract: Water-lubricated bearings have attracted increasing attention in recent years because of their environmental sustainability, simplified design, low cost, good cooling performance and low coefficient of friction. To show the characteristic of water lubrication more clearly, this paper quantitatively compares the lubrication performances of water-lubrication plain journal bearing and oil-lubricated plain journal bearing using CFD method. Bearing length, friction coefficients, power losses and temperature rises are obtained under the same working condition. Results show that water-lubricated bearing needs to be 3.4 times longer than oil-lubricated bearing, but its friction coefficient and power loss are only 11.7% of those of oil-lubricated bearing and its maximum temperature rise is less than 2 K, much lower than 96.76 K corresponding to oil lubrication.

Abstract: The article presents the issues of components for pneumatic transport. Discusses the physical characteristics of the pneumatic transport, changes in the value of pressure , density and velocity of the air. The principles of operation and construction of the suction conveyors. Discusses and proposes new solutions for suction nozzles with extended functionality. discusses the most frequently emerging issues of the pneumatic transport. Indicates the directions of the development of air transport.

Abstract: After analyzing and calculating the effect on the ability of unit frequency modulation and the dynamic characteristic of regulative system of the turbine by condenser vacuum, this paper does main research on the change of static different ratio and temporal constant of rotor when the vacuum changes. The effect on the economic characteristic, security and modulation capability are looked on more roundly when the condenser vacuum changes.

Abstract: The low cycle fatigue damage of turbine disc which is made of GH901 material is systematic analyzed and studied in the article that is based on the theory of continuum damage mechanics and fatigue testing, we improved the common Lemaitre’s low cycle fatigue damage mechanics model, the damage evolution law that the model describes is in good agreement with the test results throughout the course of the fatigue damage. The simplified analysis method for low cycle fatigue damage evolution and life prediction is proposed based on the GH901 low cycle damage features, the practical method of getting damaged material’s constants by existing data is proposed as well.