• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.10a
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• pp.70-74
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• 2004

Pressure and temperature in the cavity of injection molding have been investigated. Special injection mold was designed to install pressure and temperature sensors. The sensors were supplied by KISTLER and the pressure and temperature were measured for various operational conditions, such as injection pressure, holding pressure, cooling time, mold temperature, and injection temperature. As injection pressure increased cavity pressure and temperature increase. There were no big differences in temperatures according to the holding pressures. As mold temperature increased pressure and temperature in the cavity increase. The flowability of resin increases as mold temperature increases subsequently the pressure in the cavity increases since the pressure loss is less in the low viscous medium than high ciscous medium. The cavity temperature highly depends upon mold temperature.

• Geomechanics and Engineering
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• v.35 no.6
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• pp.593-601
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• 2023

In this paper, an analytical solution of large-strain cylindrical cavity expansion in compaction grouting problem under temperature field is given. Considering the stress increment caused by temperature, the analytical solution of cavity expansion under traditional isothermal conditions is improved by substituting the temperature stress increment into the cavity expansion analysis. Subsequently, combined with the first law of thermodynamics, the energy theory is also introduced into the cylindrical cavity expansion analysis, and the energy dissipation solution of cylindrical cavity expansion is derived. Finally, the validity and reliability of solution are proved by comparing the results of expansion pressure with those in published literatures. The results show that the dimensionless expansion pressure increases with the increase of temperature, and the thermal response increases with the increase of dilation angle. The higher the exothermic temperature of grouting slurry, the greater the plastic deformation energy of the surrounding soil, that is, the greater the influence on the surrounding soil deformation and the surrounding environment. The proposed solution not only enrich the theoretical system of cavity expansion, but also can be used as a theoretical tool for energy geotechnical engineering problems, such as CPT, nuclear waste disposal, energy pile and chemical grouting, etc.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.12
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• pp.1402-1409
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• 2008

In this paper, a low temperature co-fired ceramic cavity backed antenna in order to improve the performances of radiation and bandwidth for the antenna with high relative dielectric constant is proposed. Low temperature co-fired ceramic cavity consisted of several ground planes with closely spaced metallic vias connected. It is shown that the size of a low temperature co-fired ceramic cavity has the effects on the performances of radiation and bandwidth for the antenna. The proposed 2x4 low temperature co-fired ceramic cavity backed antenna is $10{\times}20\;mm^2$ in size. Measured results show antenna gain of $11.8{\sim}14.1\;dBi$ and bandwidth of 13 %(7.9 GHz) in the $57{\sim}64\;GHz$ band.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.09a
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• pp.132-140
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• 2005

It is well known that the family-mold has an advantage to reduce the cost for production and mold. However, defects are frequently occurred by over packing the smaller volume cavity during molding, especially whorl the family-mold has a volumetric difference between two cavities. In this study, we confirmed the cavity-filling imbalance by the temperature and the pressure sensors, and developed a variable-runner system for the cavity-filling balance. We carried out experiments fur balancing the cavity filling in the family-mold with the variable-runner system, and confirmed a balanced cavity-filing through analyzing the temperature and pressure change in each cavity as the cross-sectional area of the runner changed. We also examined the influence of the injection-speed to the balancing-capability of the variable-runner system in the experiment.

• 한국연소학회:학술대회논문집
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• 2005.10a
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• pp.255-260
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• 2005

To achieve efficient combustion within a manageable length, a successful fuel injection scheme must provide rapid mixing between the fuel and airstreams. The aim of the present numerical research is to investigate the flame holding and combustion enhancement. Additional fuel into the cavity prevents shear flow impingement on the trailing edge of the cavity. The high temperature freestream flow mixes with the cold hydrogen fuel that is injected into the cavity and raises the fuel temperature remarkably and become to start combustion. The high pressure in the cavity due to the cavity structure and combustion leads the hydrogen fuel to upstream. The shock in the cavity to be generated by the fuel injection joins together and reflects off the ceiling wall. This makes high pressure and low mach number region and makes a small recirculation in this region. This high stagnation temperature is nearly recovered in the shear layer in front of the cavity and leads to start combustion. In the downstream of the cavity, the wall pressure drops significantly. This means that the combustion phenomenon is diminished. Because fuel lumps at the trailing edge of the cavity then it spreads after the cavity so, in this region there is a strong expansion.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.3
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• pp.18-27
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• 2002

Flame behavior in inner and outer the cavity and flame temperature have an important influence on the formation and oxidation of NOx and soot. Therefore, in this study, the combustion chamber of toroidal and reentrant that have different flow characteristics of inside and outside the cavity and load, and so forth are determined as parameters of experimental conditions. An attempt has been made to obtain the effect of flame temperature and KL value in idler and outer cavity on the formation and oxidation of soot using the two-color method.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1416-1419
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• 2005

Design and manufacturing of plastic injection mold with cavity pressure/temperature sensors were performed in the present study for tensile test specimen. Standards of mold-base and tensile test specimen were used to design an injection molding system. Cavity pressure and temperature sensors were placed on the side of fixed platen of injection mold machine to prevent them from external impact damage. Injection molding experiments with variations of injection speed and melt temperature were performed and polycarbonate tensile specimens were prepared for the tensile test. It was shown that injection molding processing parameters can have effect on the mechanical properties of the plastic injection molded part.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.11
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• pp.84-90
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• 2007

In this study, design and manufacturing of plastic injection mold with cavity pressure/temperature sensors were performed fur tensile test specimen. International standard system for plastic tensile specimen was applied to design an injection molding system. Cavity pressure and temperature sensors were placed on the side of fixed platen of the injection mold to prevent them from external impact damage. Injection molding experiments with variations of injection speed and melt temperature were performed and then tensile test of the manufactured polycarbonate specimens was also performed. It was shown that injection molding processing parameters can have effect on the mechanical properties of the plastic injection molded part.

• Transactions of Materials Processing
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• v.15 no.1 s.82
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• pp.47-56
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• 2006

It is well known that the family-mold has an advantage to reduce the cost for production and mold. However, defects are frequently occurred by over packing the smaller volume cavity during molding, especially when the family-mold has a volumetric difference between two cavities. In this study, the cavity-filling imbalance was confirmed by the temperature and the pressure sensors, and a variable-runner system was developed for balancing the cavity-filling. Experiments of balancing the cavity filling was carried out in the family-mold with the variable-runner system, and balancing the cavity-filling was confirmed by changing the cross-sectional area of a runner in the variable-runner system with the temperature and pressure sensors. The influence of the injection speed to the balancing-capability of the variable-runner system was also examined in the experiment.

• Advances in Energy Research
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• v.8 no.3
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• pp.155-163
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• 2022

The current study presents experimental research on a parabolic trough collector with tube and cavity receivers. The primary concentrating parabolic reflector is designed for an aperture area of 2×2 m² with mirror-polished stainless steel sheet reflectors. The cavity receiver consists of a compound parabolic secondary reflector and a copper tube. Both the conventional tube receiver and the cavity receiver tube are coated with black powder. The experiments are carried out to compare the efficiency of the cavity receiver with the tube receiver for fluid temperature rise, thermal efficiency, and overall losses. The experiments showed significantly higher fluid temperature rise and overall efficiency and lower thermal losses for the cavity receiver compared to the tube receiver within the parameters explored in this study.