• 유공압시스템학회논문집
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• 제5권4호
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• pp.26-31
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• 2008

This paper deals with the issue of position tracking control of a clamp-cylinder for injection moulding machine with electric-hydrostatic drives. A fixed displacement pump is utilized in combination with AC motor in order to directly control a clamp-cylinder. A clamp-cylinder may be required to operate under a variety of operating conditions. Therefore, robust control performance is important in position tracking control applications. In order to accommodate mismatches between the real plant and the model used for controller design, discrete-time sliding mode control is developed by combining a velocity feedforward loop. From tracking control experiments, it is shown that significant reduction in position tracking error is achieved through the use of sliding mode control.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2003년도 유체기계 연구개발 발표회 논문집
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• pp.508-513
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• 2003

A quick injection agitator is used to mix working fluids. In this study, numerical analyses are carried out to investigate the performance of a quick injection agitator with different gaps between the impeller and vacuum enhancer. A commercial CFD code is used to compute the 3-D viscous flow field within the impeller of agitatior. Numerical results are graphically depicted with different gaps. Special attention is paid to the following topics: pressure distribution, velocity gradient, volume fraction.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제9권2호
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• pp.45-53
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• 2005

This paper investigates the influence of thermal conductivity and variable viscosity on the problem of micropolar fluid in the presence of suction or injection. The fluid viscosity is assumed to vary as an exponential function of temperature and the thermal conductivity is assumed to vary as a linear function of temperature. The governing fundamental equations are approximated by a system of nonlinear ordinary differential equations and are solved numerically by using shooting method. Numerical results are presented for the distribution of velocity, microrotation and temperature profiles within the boundary layer. Results for the details of the velocity, angular velocity and temperature fields as well as the friction coefficient, couple stress and heat transfer rate have been presented.

• Journal of Mechanical Science and Technology
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• 제19권11호
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• pp.2053-2060
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• 2005

The unsteady Couette flow of an electrically conducting, V1SCOUS, incompressible fluid bounded by two parallel non-conducting porous plates is studied with heat transfer taking the Hall effect into consideration. An external uniform magnetic field and a uniform suction and injection are applied perpendicular to the plates while the fluid motion is subjected to an exponential decaying pressure gradient. The two plates are kept at different but constant temperatures while the Joule and viscous dissipations are included in the energy equation. The effect of the ion slip and the uniform suction and injection on both the velocity and temperature distributions is examined.

• Design & Manufacturing
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• 제15권2호
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• pp.56-62
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• 2021

In this study, design technology of a non-mechanical flow meter using fluidic oscillation generated during the fluid flow in the chamber was investigated. To with respect to design a splitter, which is the most important factor in fluid oscillation, a transient flow simulation analysis was performed for three types of shapes and changes in inlet flow velocity. The oscillation characteristics with respect to the time in each case were compared, and it was confirmed that the SM03 model was the best among the presented models. In addition, the FFT analysis of the fluid oscillation results for the SM03 model was used to obtain a linear correlation between the flow velocity change and the maximum frequency, and a frequency of 20.957 (Hz/m/s) per unit flow velocity was obtained. Finally, injection molding simulation and molding experiment of the chamber with the designed splitter were performed.

• 한국분무공학회지
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• 제13권1호
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• pp.16-21
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• 2008

In the present study, the 2-fluid nozzle and 3-fluid nozzle to atomize the diesel and water with air for the fuel reformer of SOFC system were experimentally examined. In the 2-fluid nozzle, the diesel and water were alternately atomized due to bislug flow pattern, and it implies that the mixing of both liquids strongly affects the atomization pattern. On the other hand, in the 3-fluid nozzle, the diesel and water were atomized simultaneously due to the separated injection channels without mixing problem. Therefore, compared to the 2-fluid nozzle, the 3-fluid nozzle is suitable for the stable operation of the fuel reformer. In case of the 3-fluid nozzle, Type A where the air was supplied through the central channel was the most efficient.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2005년도 제31회 KOSCO SYMPOSIUM 논문집
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• pp.287-293
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• 2005

Most of all combustion system has combustion instability. It is a serious problem in combustion system. Unstable injection is one of the source of combustion instability. The experimental investigation of spray characteristics for simplex swirl injector were conducted experimentally. Two kerosene based fuels were chosen as the atomizing fluid. As the major operating parameters, fuel temperature and injection pressure were chosen, and varied in the range from 253 K to 293 K and from 0.2 MPa to 1.0 MPa, respectively. Direct spray images and mean diameter were measured for the various combination of operating parameters in the flow field. The results of present study show that the injection pressure and spray cone angle are fluctuated at specific conditions while it is continuous steady injection. As the fuel temperature changes continuously, spray cone angle varies discontinuously through the region of injection instability.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 춘계학술대회 논문집
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• pp.625-626
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• 2008

• 한국기계가공학회지
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• 제11권6호
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• pp.123-129
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• 2012

This study was carried out to improve the design of fuel injection pump for marine medium diesel engine. For this purpose, all parts of fuel injection pump were modeled and simulated using CATIA V5R19, FLUENT & MSC Nastran. Flow analysis for plunger cylinder and structural analysis for plunger, roller and spring, which were considered as essential parts of fuel injection pump, were performed to find the optimal design of fuel injection pump. As the results, flow of fluid in plunger cylinder was showed good results in case of 7.7~8.0m/s of plunger velocity. Furthermore, it was confirmed that plunger, roller and spring could be operated safely under 1,800bar pressure.

• 한국산업융합학회 논문집
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• 제23권3호
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• pp.507-513
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• 2020

Liquid filling machines are frequently used in packaging fields; however, there exists a problem in precisely measuring the quantity of the liquid. In the case where the liquid filling machine is not properly metered, there may be issues, such as the fluid exceeding the capacity or chemicals being exposed outside. In this paper, we propose a smart injection nozzle device that can solve the issues stated above. The proposed smart injection nozzle can raise the nozzle according to the water level to remove bubbles and inject the accurate amount of fluid. In addition, the efficiency of the logistics process is enhanced by the smart QR code. Through experiments using the developed smart injection nozzle device, we have noticed that the accuracy of injection capacity, nozzle position, reaction time and building data exceeded the target value. Therefore, it expected that this machine will give more production and save a lot of manpower for packaging industry.