• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.28 no.8 s.227
• /
• pp.984-988
• /
• 2004

This study presents the process of the solenoid parameter estimation of an common-rail injector fer HSDI(High Speed Direct Injection) diesel engines. The EMF(Electromotive Force) and solenoid inductance are the major parameters for presenting the injector dynamics, and also these parameters are estimated by using a multi-layer feedforward artificial neural networks(ANN). The performances of parameter estimators are verified by the simulation with injector model. The feasibility of this methodology is closely examined through the simulation in the various operating points of injector. The simulation results have revealed that estimated parameters show favorable agreements with the common-rail injector model.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2007.11a
• /
• pp.824-828
• /
• 2007

In this paper Statistical Energy Analysis has been considered to predict middle, high frequency air borne interior noise. PIM method is used for verification. Damping loss factor and coupling loss factor have been derived from the response(SPL) of sub systems when the power is applied. The airborne SEA model of vehicle is modeled through AutoSea2. Insulation material's absorption coefficient and transmission loss are acquired from closed form solution and experiment.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1995.10a
• /
• pp.813-817
• /
• 1995

Structural analysis of horizontal cold chamber die casting machine is performed by the FEM. The analyzed model is made up of stationary die platen,movable die platen,link housing platen, C-frame, and tie bar which mainly undertake die locking force and injection force. In modeling, compression gap elements are used for to simulate contacting condition between tie bar and movable die platen, movable die platen and base frame, and link housing and base frame. Unbalanced die locking force imposed on four tie bars are considered. As the results, the deformed shape and the stresses of the die casting machine are given.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.23 no.1
• /
• pp.69-81
• /
• 1999

In this research computational methods for the droplet atomization and spray wall impingement are studied for the non-evaporating diesel fuel spray. The TAB(Taylor Analogy Breakup) model and Wave model are compared with experiments in order to describe droplet atomization process. The Watkins model and O'Rourke model are compared to simulate the spray wall impingement. As a result, It is found that the application of the Wave model has a good agreement with the experimental data in the case of high pressure injection. With regard to wall Impingement phenomena, it is found that the Watkins model is appropriate to the high temperature cylinder wall condition, while the O'Rourke model is appropriate to cold starting problem.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2001.04a
• /
• pp.66-69
• /
• 2001

A subsurface containment system which is constructed by pumping a gelling liquid (Colloidal Silica) into the unsaturated medium is investigated by developing a mathematical model and conducting numerical simulations. The proposed model is verified by comparing experimentally and numerically determined hydraulic conductivities of gel-treated soil columns at different Colloidal Silica (CS) injection volumes. The numerical experiments indicate that an impermeable gel layer is formed within the time period twice the gel-point. At the Same normalized time, the CS solutions with lower NaCl concentrations result ill further migration and poor Performance in plugging the pore space.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 1994.04a
• /
• pp.715-725
• /
• 1994

The objective of this research is to develop a cost model for integrated CAD system. A computerized system realizing this model then is used to aid designers. The first area is to propose a conceptual framework of a multilevel cost model. The methodology of constructing the model is discussed. Then suggestion of an object oriented programming technique for implementing the model is presented. Complicate estimation procedure can be systematically handled by this technique. Interval analysis to deal with the uncertainty of information and decision during design process is used. An experimentation algorithm for calculating the cost distribution is proposed to overcome the shortcoming of interval analysis. Major focus of this research is on net shape manufacturing processes including die casting, injection molding, and metal forming.

• Proceedings of the KSME Conference
• /
• 2001.11b
• /
• pp.622-627
• /
• 2001

Microjet flows are often encountered in many industrial applications of micro-electro-mechanical systems as well as in medical engineering fields such as a transdermal drug delivery system for needle-free injection of drugs into the skin. The Reynolds numbers of such microjets are usually several orders of magnitude below those of larger-scale jets. The supersonic microjet physics with these low Reynolds numbers are not yet understood to date. Computational modeling and simulation can provide an effective predictive capability for the major features of the supersonic microjets. In the present study, computations using the axisymmetic, compressible, Navier-Stokes equations are applied to understand the supersonic microjet flow physics. The pressure ratio of the microjets is changed to obtain both the under- and over-expanded flows at the exit of the micronozzle. Sonic and supersonic microjets are simulated and compared with some experimental results available. Based on computational results, two microjets are discussed in terms of total pressure, jet decay and supersonic core length.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.24 no.4
• /
• pp.512-518
• /
• 2000

A wall fuel-film flow model is developed to predict the effect of a wall-fuel-film on air-fuel ratio in an SI engine in transient conditions. Fuel redistribution in the intake port resulting from charge backflow and a simple liquid fuel behavior in the cylinder are included in this model. Liquid fuel film flow is calculated of every crank angle degree using the instantaneous air flow rate. The model is validated by comparing the calculated results and corresponding engine experiment results of a commercial 4 cylinder DOHC engine. The predicted results match well with the experimental results. To maintain the constant air-fuel ratio during transient operation. the fuel injection rate control can be obtained from the simulation result.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2002.09a
• /
• pp.161-166
• /
• 2002

Bioremediation of trace metals in groundwater may require the manipulation of redox conditions via the injection of a carbon source. To simulate the numerous biogeochemical processes that will occur during the bioremediation of trace-metal-contaminated aquifers, a reactive transport model has been developed. The model consists of a set of coupled mass balance equations, accounting for advection, hydrodynamic dispersion, and a kinetic formulation of the biological or chemical transformations affecting an organic substrate, electron acceptors, corresponding reduced species, and trace metal contaminants of interest, uranium in this study. The redox conditions of the domain are characterized by estimating the pE, based on the concentrations of the dominant terminal electron acceptor and its corresponding reduced specie. This pE and the concentrations of relevant species we then used by a modified version of MINTEQA2, which calculates the speciation/sorption and precipitation/dissolution of the species of interest under equilibrium conditions. Kinetics of precipitation/dissolution processes are described as being proportional to the difference between the actual and calculated equilibrium concentration.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.22 no.3_1spc
• /
• pp.531-536
• /
• 2013

An automatic wax-ring manufacturing system for silk coating was developed, which consisted of a container, pallet with a cooling part, injection port, and removing device. The removing device is a system to load, lift, and cut the wax-ring, which is widelyused for various silk-coating industrial purposes. A novel removing device equipped with a water cooling circulation system is proposed in this paper. It has the benefit of easy control, as well as the convenience of loading and unloading without the use of other equipment. Three-dimensional modeling techniques were adopted to develop integrated functions for the automatic wax-ring manufacturing system, which made it possible to confirm the smooth integration/interface of each part and the system's interrelations with other manufacturing systems.