Applied Mechanics and Materials Vols. 568-570

Abstract: As an important technological means for engines’ low emission with high efficiency, variable valve agency is widely applied in the new-type machine’s R&D and the old-type machine’s modification. This paper applies AVL BOOST one-dimensional simulation software to the working process of the small displacement electronic control gasoline engine and proceeds with the analog simulating calculation. The data error between the calculated result and the original experiment one is less than 5%, so the calculation precision meets the requirements. As formulating simulation study programs and analyzing the valve timing parameters’ impact on the low-emission electronic control gasoline engine’s performances, this paper finds the intake duration angle, the exhaust advance angle, and the valve overlap, all receive big impacts; the original machine’s valve timing optimizes the treatment of working conditions with high speed while sacrificing the power performance of low-speed working conditions. On this basis, this paper designs the variable valve mechanism, and improves the original machine’s medium-and-low rotating speed’s torque by 10% or so.

Abstract: Starter is an important component of auto engine, its service life can be reflected by the durability test. According to the running conditions, requirements of the starter durability test were analyzed. So, an electrical control test system based CP1H PLC was established. The system includes PC monitor module achieved by configuration software, control module build by Omron CP1H PLC and actuator module with four engine test rigs. Then, the PLC hardware circuit was designed and the flow of control program was given. The test system has characteristics of versatility, automated control and high testing precision.

Abstract: The effects of painting ink’s color on UV absorptivity and UV-light wavelength on curing depth in the process of rotating curing are analysed. Aiming at radial uneven curing, the scheme is proposed that using the UV LED with wavelengths of 365nm and 395nm to form a fan-shaped array on cylindrical surface. The curing system can achieve UV irradiance be enhanced gradually along the radial, and the technique problem of uneven curing is solved. The simulation result shows that the curing system meets design requirements on Tracepro.

Abstract: The performance of Electrostatic Precipitator (ESP) is significantly affected by complex flow distribution. Recent years, many numerical models have been developed to model the particle motion in the electrostatic precipitators. The computational fluid dynamics (CFD) code FLUENT is used in description of the turbulent gas flow and the particle motion under electrostatic forces. The gas flow are carried out by solving the Reynolds-averaged Navier-Stokes equations and turbulence is modeled by the k-ε turbulence model. The effect of electric field is described by a series equations, such as the electric field and charge transport equations, the charged particle equation, the charge conservation equation, the mass and momentum equations of gas, the mass and momentum equations of particle and so on. The particle phase is simulated by using Discrete Phase Model (DPM). The simulations showed that the particle trajectory inside the ESP is influenced by both the aerodynamic and electrostatic forces. The simulated results have been validated by the established data.

Abstract: In order to study the reflection of electromagnetic wave in Lorentz media, A finite-difference time-domain method based on the auxiliary differential equation (ADE) technique is used to obtain the formulation of 2-D TM wave propagation in lossy Lorentz media. In 1-D case, the reflected coefficients calculated by ADE-FDTD method and exact theoretical result are excellent agreement. This expresses that the 2-D formulas of electromagnetic wave propagation in lossy Lorentz media are right. Furthermore, Plane wave reflected by Lorentz media layer is calculated and simulated. Results display that reflected effect is evident.

Abstract: The cutting processes of drill rod under different surge pressures, rotate pressures and propulsion forces were recorded by the high-speed camera in the hydraulic percussive rotary cutting tests of deep-ocean cobalt-rich crusts. Meanwhile, the curves of impact vibration, torsional vibration and frame vibration during the cutting processes were plotted by digital picture processing technique. The impact frequency, torsional vibration frequency, torsional vibration amplitude, vibration amplitude of drill rod and the frame were calculated. The photogrammetry results are generally in agreement with the traditional test results. High-speed photogrammetry is a non-contact, wide range application, and high precision measurement, and the cutting process can be described visually and adequately.

Abstract: Anchor dragging threatens vessel anchoring security directly, so how to find and predict anchor drgging is an important issue of navigation fields. Most existing judgement methods depend on distinguishing feature of dragging vessel from normal anchoring, so vessels usually have moved a certain distance when duty officers find anchor dragging. Thus it is necessary to develop a practical anchor dragging early warning techonology. Based on the special change of anchor cables. Vibration frequency while anchor dragging, a new anchor dragging early warning system (ADEWS) was designed. The system was composed of two main facilities: acceleration sensor and teminal unit. The acceleration sensor was fixed on anchor cables to monitor its vibration frequency, and the teminal unit in the bridge was designed to analyze change characteristic of frequency and release early warnning. For facilitis of this new ADEWS is simple, it is easy to be equipped on vessels. Furthermore, the system can automatically analyze vibration frequency and release early warning, so it has advantages of high feasibility and reliability. These advantages can lessen duty officers work burden and reduce the dependece on duty officers individual experience. Therefore, ADEWS based on Vibration frequency analysis possesses a good application prospect in practical engineering.

Abstract: The combined effects of the inhomogeneity and higher-order transverse perturbation on the nonlinear solitary waves are investigated. People are very interested in the nonlinear reverse structure (such as solitary wave, shock) in dusty plasma. Dusty plasma is a kind of ionized gas which contains electronics, plasma and dust particles. As the characters of big quality and high negative of dust particles, whose existence will significantly affect the behavior of plasma and stimulate the rich wave model. Today the study to nonlinear wave in inhomogeneity dusty plasma is focused on one-dimensional and it is very small to three-dimension. A modified variable coefficients Kadomtsev-de Vries (KdV) equation is obtained by using the reductive perturbation method.The conclusion can be got from the simulation that inhomogeneity has strong influence on the nonlinear properties of dust acoustic solitary waves.

Abstract: Seismic rock study aims to clarify the relationship between the rock and the intrinsic nature of seismic attributes contained in the fluid between the paper based on the physical characteristics of the rock, viscoelasticity and anisotropy of systems theory and media rock mechanics model response characteristics, and model simulation, simulation results show that the physical structure of the rocks we build the model can well reflect the characteristics of the seismic response of rock mechanics.

Abstract: Evaporative cooling is able to generate the cooling medium at a temperature approaching to the ambient wet bulb temperature. In this paper, a low-energy air-conditioning strategy is proposed, which is a combination of cooled ceiling (CC),microencapsulated phase change material (MPCM) slurry storage and evaporative cooling technologies. The assessment of evaporative cooling availability and utilization is done for five representative climatic cities, including Hong Kong, Shanghai, Beijing, Lanzhou and Urumqi in China, and the energy saving potential of the proposed air-conditioning system is analyzed by using a well validated building simulation code. The results indicate that the new system offers energy saving potential up to 80% under northwestern Chinese climate and up to 10% under southeastern Chinese climate. The optimal design method of the slurry storage tank is also proposed based on the slurry cooling storage behaviors and cooling demand variations of the ceiling panels.