Abstract: The roll variation of airborne platform has significant impact on the coverage area and point density of the laser point cloud obtained by airborne LiDAR. Thus, it is of practical significance to compensate the impact of roll variation. In this paper, a compensation device was designed firstly, including the mechanical structure and control system, to compensate the impact of roll variation on the laser point cloud. Then, the compensation principle of the airborne LiDAR with the designed compensation device was analyzed. Finally, the actual working procedure of the airborne LiDAR with the designed compensation device was simulated, in which the measurement errors of the position and orientation system (POS), as well as the measurement errors and control errors of the designed compensation device has been considered. The experimental results show that the designed compensation device is effective to compensate the impact of the roll variation.
Abstract: Lanping Pb-Zn mine is the biggest Pb-Zn mine of China. It is necessary for the mine to digital. On the basis of systematic analysis of and research on Jiayashan ore block in Lanping pb-zn mine, Mine Mathematical Model software, Surpac software and Micrmine software from abroad for digitization ware used to study this deposit. Finally, a three-dimensional space deposit model was established. As a result, the dynamic management of mine has been realized, the degree of automation and systematize have been increased for mining production, the scientific help have been presented for making use of resources sufficiently and reasonably.
Abstract: On the basis of the analysis on the development environment and development key technologies, Three-dimensional mechanical model exhibitation system based Google Map API was developed, which achieves uniform management of 3D model data, 3D model browsing, information query, online assembly, model download and can support multi-sited collaborative simulation. By using local search service and existing landmark file of Google Map and adding self-defined landmarks list, it realized fast retrieval, precise positioning and regional analysis of model supplier. Taking into account the system maintainability, scalability and security issues, it makes the design resources to be maximize shared and has certain practicability.
Abstract: The scheme of structure and transmission is designed in the paper. A kind of stubble-smashing machine is virtually manufactured by the software Pro/E 4.0. On the base of it, the deformation analysis and strain analysis of smashing cutter are done with the software ANSYS Workbench13, which shows that the machine can meet the work requirements. The paper supplies theoretical basis for the design of corn stubble-smashing machine.
Abstract: The dynamical model of underwater monitoring platform is formulated aimed at the dynamical response by the action of flow force, based on Hopkinson impact load theory, taken into account the catenoid effect of mooring cable and revised the difference of tension and tangential direction action force by equivalent modulus of elasticity. And solved the equation by hydraulics theory and structural mechanics theory of oceaneering, studied the action force characteristic of mooring cable and motion characteristic of buoy. Through the result the conclusion can be got the buoy will engender biggish heave and swaying displacement, but the swaying displacement got stable quickly and the heaven displacement got vibration for the vortex-induced action by the flow; because the vortex-induced action and the impact action between buoy and the mooring cable, the tension made great changes when the mooring cable was Relaxation-tension.
Abstract: A new method of integrate simulation for the kinematics and dynamics analysis of complex mechanical system is presented in this paper. This platform of the method is based on Visual Studio 2005, MD ADAMS( Automatic Dynamic Analysis of Mechanical System) R3 and Pro/Engineer Wildfire 4.0. The experimental model is built with Pro/E, and then some functions of Pro/Toolkit are used to export file of parasolid format and coordinates of some specified Datum Points. Finally, the coordinates of these Datum Points are written into a CMD file (Commands file of ADAMS). A slider-crank mechanism is used as a numerical example to demonstrate the application of the method. It is shown that this approach is a much easier, faster than usual manual method especially for complex mechanical system which has a lot of Marker Points and constraints.
Abstract: Slope classification map is the essential condition of land resource reasonable using. This article aims at solving problems in progresses of conventional slope classification map making methods. Providing an improving method which bases on ArcGIS to make slope classification map, and discussing the progresses of improving method in detail with cultivated land slope classification as a example. This method works with merge, aggregation, and elimination to improve the effect of the slope map. The result of the experiment proves the feasibility and effectiveness of this method.
Abstract: In order to grasp the change of oil-gas interface in north area of Lamadian Oilfield and determine the conditions of gas or oil invasion during the development of gas storage, the precise geological model is established. By simulation software Eclipse immigrations of gas-oil interface are tracing simulated and cases of gas or oil invasion are monitored under various pressure differentials, based on which the limits of pressure are provided at last. Simulation results indicate that when the pressure of gas region is higher than oil region the gas invasion will happen and when the pressure differential between oil and gas region is up to 0.6 MPa the oil invasion will happen after 16 injection-production cycles. This paper is valuable to practical project applications which keep the interface stable and avoid the gas and oil invasions.
Abstract: This work demonstrates the effect of fingers, device-width and inductance on reverse recovery of LDMOS by unclamped inductive switching (UIS) circuit simulation for two dimensional (2D) and three dimensional (3D) devices. All the observations have been done for maximum pulse width at which device pass under UIS test. For UIS simulations the failure criteria is taken as the device temperature reaching a critical value of 650K. It has been shown that reverse recovery charge (Qrr) increased linearly with number of fingers, device width and inductance.
Abstract: The turbulent jets with swirl are of particularly significant and practical interest in various fields of industry. The present numerical study concerns the comparison between three models of turbulence for the forecast of a turbulent free axi-symmetric jet with turbulence and his development. The software used was CFD code Fluent with his three turbulence models namely k-, k- and RSM. This different turbulence models are tested to better simulate and view the effectiveness of models in the description of the jet behaviour. The parameters of flow examined are the velocity profile of jet at Reynolds number of 22000. Comparisons between numerical predictions and experimental measurements taken from the technical literature for the case of natural jet development show that the numerical techniques of Computational Fluid Dynamics are an important tool for studying the jet’s behaviour. The results indicate that the RSM models is higher than the k- and k- models when looking at changes in velocity profile behaviour towards experimental profile, the k- model can be used for predicting re-circulating flows if we are interested in global settings only. The prediction obtained by k- model is far from experimental results. It is misadvised to use k- model for the jets analysis. The better numerical results were obtained by CFD code CFX, where results are in good agreement with the experimental results.