Papers by Keyword: Three Dimensional Simulation

Abstract: In this paper, we use a Spline curve and OpenGL construct a three-dimensional (3D) geometrical model, and get the surface appearance 3D simulation on a computer screen of X-type four hollow fabric in the end. It manifests the interlacing state of warp and weft yarns in fabric, thus proves the feasibility of Spline curved line in simulation and provides a practical method for surface simulation of multi-layer fabric in the future.

Abstract: To achieve the trees three dimensional simulation, the most critical step is to extract the trees skeleton. This paper focuses on the point cloud contraction-based skeletal extraction algorithm, uses neighbors to build a transformation matrix, extract a discrete point set approximated to the real skeleton by Laplacian contraction, and constructs a 1D curve skeleton with the help of a weighted undirected graph and edge collapse algorithm. 1D curve form is more easy to operate, guide the reconstruction of three-dimensional model, solve the problem of incomplete data in the process of modeling .

Abstract: The thermal discharge from the Houshi power plant in China has been increased continuously with the increase in power supply. In order to understand the waste heat pollution conditions in the coastal areas of the Houshi power plant, we proposed a modified Princeton Ocean Model (POM) model to conduct three-dimensional numerical simulations for heat transport in the coastal areas of the plant. The proposed model has been verified to be valid in our previous study. This study employed the verified model to predict heat transport under the future operational conditions of the power plant with a thermal discharge of 217m³/s. The prediction results indicate that a larger area of waters near the plant outfall will have a temperature rise larger than 4°C, and this area of temperature rise is close to the water intake of the power plant. Besides, the heat accumulation phenomena will be serious in the depth direction and this will bring great influence to marine ecological environment, especially to benthic organisms. It is suggested that some measures are necessary to reduce temperature rise in the coastal areas of the Houshi power plant in the future.

Abstract: A new multi-furcated structure of tree-shaped mini-channel was proposed in this paper. Numerical simulation was conducted to analyze the flow boiling and bubble growth characteristics of water in the mini-channel. By using the constant wall temperature heating method, the model was divided into different sub-regions according to different wall temperatures. Typical bubbly flow and slug flow patterns were obtained through the monitoring of the boiling process. The simulation results showed that when the convective heat transfer dominated, the pressure drop maintained minor and stable; while the nucleate boiling dominated, the pressure drop increased significantly and fluctuated within a certain range. Moreover, with the increase of vapor quality, the heat transfer coefficient increased first and then decreased. It is also found that the geometric structure of the multi-furcated tree-shaped mini-channel had a great impact on the heat transfer characteristics, and simulation results agreed well with the theoretical values.

Abstract: The thermal discharge from the Houshi power plant has been increased continuously with the increase in power supply. In order to understand the waste heat pollution conditions in the coastal areas of the Houshi power plant, we proposed a modified Princeton Ocean Model (POM) model to conduct three-dimensional numerical simulations for heat transport in the coastal areas of the plant. The proposed model was verified using observation data in 2002 under previous operational condition of the power plant with a thermal discharge of . The verification results indicate that the simulation results of heat transport have a good agreement with observation ones.

Abstract: This paper studied at the problem of visual simulation of astronaut fling outside in the cabin. Firstly, according to morphological characteristics of the human’s body, we used SolidWorks to construct the simplified geometric model of astronaut. Then we made the model of astronaut carried out the 3-dimensional real-time flight animation based on OpenGL by view transformation and model transformation in VC++ environment.

Abstract: The presence of cavitation and turbulence in a diesel injector nozzle has significant effect on the subsequent spray characteristics. However, the mechanism of the cavitating flow and its effect on the subsequent spray is unclear. The initiation, development and collapse of the cavity are strongly influenced not only by the injection pressure and back pressure but also by the nozzle geometry. The numerical simulation of cavitating flow in nozzle holes of a vertical multi-hole injector with mixture multi-phase cavitating flow model was carried out. The effects of sac geometry, hole entrance curvature radius and hole inclination angle on the cavitating flow in nozzle holes were investigated. It is finally concluded that the performance of IMPROVED nozzle is better than that of STD nozzle and VCO nozzle and small inlet turning angle of the orifice can enhance the atomization of the spray.

Abstract: Three dimensional simulation of the velocity field of solid-liquid two-phase flow inside the abrasive water jet nozzle was studied by the computational fluid dynamics software (CFD). The complicated velocity field and vectorgraph of the flow in the abrasive water jet nozzle was obtained. In the course of the simulation, the Syamlal-O’Brien model was used to decide the inter-phase drag exchange coefficient. The velocity vectorgraph simulation results indicate that the highest flow speed is occurred at the inlet of the mixing chamber and the flow speed is gradually decreased along the direction of the nozzle axis and got to the lowest speed at the outlet of the nozzle. And also the flow speed in the cross section of the mixing chamber is gradually reduced along the radial direction of the cross section and got to the lowest speed in the verge of the chamber. The comparison of simulation result for the velocity field of water and abrasive exhibits that the velocity of water in the mixing chamber is three or four times higher than that of abrasive.

Abstract: Plastic deformation behavior during equal channel multi-angular pressing (ECMAP) was analyzed using the three dimensional finite volume method of the commercial code MSC.Superforge. In order to understand local and global deformation characteristics, effective strain and pressing load histories were investigated. The predicted plastic deformation behavior of the workpiece material during ECMAP of route A, route B and route C with a theoretical total strain of ~2.2 upon a single pass at three different friction factors (m=0, 0.1 and 0.2) was compared. The predicted strain results show different values in outside and similar values in central regions of the processed workpieces with different friction and forming routes. The pressing loads are higher under higher friction condition, showing almost no difference with three different pressing routes.