Papers by Author: Jun Da Chen

Abstract: The development of fault detection and diagnosis system is accomplished with the application of PXI interface technology, modular instrument and signal processing technology. The total technical scheme of host computer, portable test platform, signal adapter unit, test interface and cable together with peripheral components is introduced in the presented system. Consequently, the hardware includes master computer (fault test and diagnosis platform), PXI-bus data acquisition system, signal interface adapter, power supply system, interface unit, connection cable and peripheral dedicated test equipments. And the software is developed by C and LabWindows/CVI based on Win32 operating system. In addition, the modular and object-oriented programming are adopted in the software development. The software consists of three parts: the master program running on test and diagnosis platform, the client software module on signal adapter unit as well as the remote interface software module. It can implement fault detection of electrical system on replaceable circuit board and block of the hydraulic system or electrical system. So it can help equipment repairmen and operator perform quick repairs and maintenance to the electrical system for engineering equipment.

Abstract: Techniques of numerical simulation on mold filling process of casting are investigated in this paper. The mathematical model is formed on the ground of some selected theories in computational fluid dynamics (CFD), Numerical Heat Transfer (NHT) and computational methods to interfacial tracking. The discrete solution to the governing equations appeals to Finite Volume Method (FVM) on structured mesh. As for viscous turbulence flow and multiphase fluid flow in mold filling, engineering turbulence model and Volume of Fluid (VOF) method are adopted in the algorithms, respectively. As a debut, the general-purpose CFD software is used to establish the practicable mechanical model for the simulation. By means of numerical simulation, variation and distribution of velocity, temperature, stress and configuration of casting, etc. with respect to time and space in the filling process can be quantitatively analysed in detail, which is helpful for engineers to optimize their design of technics with less time and less cost and is meaningful to provide the subsequent simulation, solidification process of casting, with initial conditions.