• Transactions of Materials Processing
• /
• v.10 no.7
• /
• pp.525-533
• /
• 2001

PET bottles are main]y manufactured by the stretch blow-molding process. In order to improve the thickness distribution to avoid crack generation at bottom region of one-piece PET bottle, process analysis of stretch blow-molding using a finite element method has been carried out. Finite element analysis has been carried out using ABAQUS/Standard. CREEP user subroutine provided in ABAQUS has been used to model PET behavior that is rate sensitive. Among the process parameters, the effect of plunger movement to thickness distribution of bottle has been considered by axisymmetric analysis. A modified process of plunger movement, which yields more uniform thickness distribution, has been proposed. 3D FE analysis has been done to confirm the validity of the proposed process.

• Journal of international Conference on Electrical Machines and Systems
• /
• v.1 no.3
• /
• pp.282-288
• /
• 2012

A special pulsed electromagnetic actuator is presented whose plunger consists of two parts made of carbon steel and permanent magnet, respectively. The actuator exhibits a high holding force and small consumption of energy. The movement of the plunger is controlled by short current pulses. The static characteristics and other operation properties of the device are modeled numerically.

• 한국전산유체공학회:학술대회논문집
• /
• 2011.05a
• /
• pp.395-406
• /
• 2011

In this research a numerical simulation method is developed for moving body in free surface flows using fixed staggered rectangular grid system. The non-linear free surface near the body is defined by marker-density method. The body boundary is defined by line segment connecting the points where the body surface and grid line meet. Continuity equation and Navier-Stokes equations are used as governing equations and the equations are coupled with two-step projection method. The velocities and pressures of body boundary and free surface cells are calculated with simultaneous iterative method. To treat a body movement in a fixed grid system, the volume displaced by moving body is added to the divergence of the body boundary cell. For the verification of the present numerical method. vortex shedding period of advancing cylinder is calculated and the period is compared with existing experiment results. Moreover, added mass and damping coefficients of a vertically excited box are calculated and the computed results are compared with published experiment results. Impulsive pressure and water level variation due to sloshing phenomenon are simulated and the results are compared with published experiment results. Varying the plunger shape, the waves generated by plunging type wave maker are compared with the 2nd order Stokes wave theory The plunger shape generating the wave that shows the best agreement with the theory is represented.

• Proceedings of the KSME Conference
• /
• 2001.06d
• /
• pp.927-932
• /
• 2001

It is intended to develope an algorithm for dynamic simulation of fast-acting solenoid valves. The coupled equations of the electric, magnetic, and mechanical systems should be solved simultaneously in a transient nonlinear manner. The transient nonlinear electromagnetic field is analyzed by the Finite Element Method (FEM), which is coupled with nonlinear electronic circuitry. The dynamic movement of the solenoid valve is analyzed at every time step from the force balances acting on the plunger, which include the electromagnetic force calculated from the Finite Element analysis as well as the elastic force by a spring and the hydrodynamic pressure force along the flow passage. Dynamic responses of the solenoid valves predicted by this algorithm agree well with the experimental results including bouncing effects.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.26 no.7
• /
• pp.959-965
• /
• 2002

It is intended to develop an algorithm for dynamic simulation of a fast-acting solenoid valve. The coupled equations of electric, magnetic, and mechanical systems should be solved simultaneously in a transient nonlinear manner. The transient nonlinear electromagnetic field is analyzed by the Finite Element Method (FEM), which is coupled with nonlinear electronic circuitry. The dynamic movement of the solenoid valve is analyzed at every time step from the force balance acting on the plunger, which includes the electromagnetic force calculated from the Finite Element analysis as well as the elastic force by a spring and the hydrodynamic pressure force along the flow passage. Dynamic responses of the solenoid valves predicted by this algorithm agree well with the experimental results including bouncing effects.

• Analytical Science and Technology
• /
• v.20 no.1
• /
• pp.70-77
• /
• 2007

Twelve chlorophenols (CPs) were extracted by liquid phase microextraction (LPME) from the industrial waste-water and analyzed by GC/MS. To establish the optimal conditions, species of extraction solvent, sample amount, pH of sample, salting out effect, a number of sampling and plunger movement speed were investigated. As a result, the linearities of calibaration curves ranged from 0.9913 to 0.9999, while LODs and LOQs were from 0.05 to 10.0 ng/mL except 2,3,4,5-tetrachlorophenol and pentachlorophenol. Using this method, 4-chloro-3-methylphenol confirmed from waste water at the concentration of 784 ng/mL. The method can be applicable to detect chlorophenols from industrial waste-water.