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In order to ensure safely and effective operation of the transmission line, the condition monitoring of transmission lines is widely applied to discover the dangerous points of transmission lines and monitor surrounding weather conditions. Since transmission lines run across fields, adopting mobile communication network to carry out the data transmission is very convenience. The operation cost is...
Numerical Study of mixed convection in square enclosure filled by air, which has two sinusoidal walls with different locations in outer walls, when a circular rotating cylinder is entered to the enclosure is being approached throughout this paper. A two dimensional, time independent, laminar mixed convection with variable Richardson number during the range from (0.1 to œ) at Ra=105 and D=0.4L by using...
Cat free fall righting maneuverer has inspired many aerial, space and legged robotic research. Conservation of angular momentum principle is used to derive the inverse differential kinematic and TMT vector form dynamics of the motion for three robotic models: a two-link model, a three-link model with tail, and a comprehensive eight-link model with the addition of legs. The path planning problem in...
The influence of void distribution on the transverse mechanical properties of unidirectional composites is studied. Firstly, using Matlab to obtain composites microscopic voids radius distribution. Secondly, based on void radius distribution, the representative volume element (RVE) of composites microstructure with random fiber, matrix, and random voids are generated by random algorithm. Finally,...
Numerical analysis of convective heat transfer process was conducted to accurately describe the energy balance of the airfoil ice protection area. The convective heat transfer coefficient around the leading edge was calculated using four different turbulent models, including the Spalart-Allmaras model, the k-ε model, the k-ω model, and the transition SST model. Results were compared with icing tunnel...
The mechanical properties and microstructure of heat treated 6082 wrought aluminum alloy was studied. The aim of this work was to study the merits and demerits of natural aging and artificial aging on material properties. The precipitation hardening of aluminum alloy usually undergoes a thermal treatment consisting of heat treatment, quenching and aging. Experiments were carried out for different...
This paper presents an empirical method for determining the axial load distribution generated by the V-band clamps around the flanges. The method utilizes a hydraulic fixture and uniquely designed flanges. The load is measured through strain gages and a pressure transducer. Tests were conducted successfully on a V-band and a nonuniform distribution of axial load was obtained, fitting well with the...
This study has aimed to investigate the behaviors including evaporation rates, refractive index, volume fractions and mixing characteristics of the binary mixture single droplets containing pentadecane (C-15) and dodecane (C-12) in a heated chamber at a high ambient temperature of 98°C. The volume ratios of pentadecane to dodecane were 3:1, 1:1 and 1:3. The droplet diameter was measured at the forward...
Recently multi-axis machining technology has improved significantly. It has become a widely accepted method of manufacturing components with complex, free form surfaces. Solid billet materials with negligible internal defects are used in this process. This provides increased durability and fatigue life over equivalent cast components. However, multi-axis machining using ball nose cutting tools leaves...
Combining multi-field information fusion theory with the ammunition feeding system, a multi-level information fusion method for fault detection and prediction is proposed in this paper. Firstly, it is studied that the occurrence and development mechanism of damage and failure of complicated ammunition feed system under rapid impact. The wear damage and stop shooting faults are diagnosed by measuring...
The use of bio-based materials for production of biocomposites is of interest due to their low cost, abundance and the fact that they are renewable and biodegradable. In this work, an epoxy matrix was produced from residual soybean oil and subsequently used in the preparation of composites reinforced with spent coffee grounds (SCG) fiber. SCG were chemically treated with alkaline hydrogen peroxide...
An analytical solution and numerical models are proposed for the buckling and post-buckling behavior of honeycomb sandwich structures under edgewise compression. General buckling and core crushing due to transverse shear are observed in the experiment. Based on these phenomena, the von Kármán plate theory are employed for the analysis for the buckling behavior and the analytical solution for the core...
Considering the expansion of new trends in production technologies, it is necessary to know as much as possible effects that influence quality of produced component. Sintering of metal powder brings many problems which is necessary to identify and consequently to solve. It is more important, if the parts are complex with thin walls and it is supposed that it will be used in the equipment with high...
After contact with receiver aircraft, the nozzle of flying boom is locked into the receptacle of receiver which may generate a dangerous radial constrained force (RCF) with disturbance from environment. This paper presents a novel control method to eliminate the RCF. Based on the existing altitude dynamic function, the unloading dynamic model can be achieved by putting the RCF into the existing dynamic...
The principle and application of harmonic motion drive is introduced. Aiming at spacecraft harmonic motion drive mechanism working in space environment, a set of transmission efficiency test and control system is designed. The structure and principle of the whole control system is described. the efficiency test method of a harmonic motion drive is designed. To improve the traditional test device,...
LEO Satellites equipped with high-power microwave payloads bring special demands for fast charging of Lithium ion battery. However, charging polarization occurs in traditional constant current-constant voltage strategy for Li-ion battery, following by comparative long charging time. To realize fast charging of batteries, novel Li-ion battery fast charge topology and principle were present based on...
In this study, a new fundamental modeling framework for solid field is proposed by means of which a two-way dynamic coupling between the solid and fluid fields can be attainable for identically-modeled fluid field. To this aim, using the physical decomposition framework proposed in [1], a domain-independent model that can demonstrate the reversible and irreversible energetic interactions between the...
A hot-fire test of an experiment-scale Kero/GOX liquid rocket engine is carried out. Numerical simulation on the basis of the experiment is calculated with the purpose of verifying the validity of the numerical simulation model in this paper. After that, high frequency instability induced by the distribution of gas-liquid scheme injectors is studied numerically. There are three injectors distribution...
To solve the ascent guidance of reusable launch vehicle (RLV) under the uncertain condition, a robust guidance method based on combing feedback linearization and H-infinity optimization theory is proposed. The article establishes the RLV ascending dynamic models. According to the characteristics of the ascending flight, the height deviation is converted into a linear relationship with pitch angle...
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