• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.184-187
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• 2006

The heat transfer characteristics of solar tower receivers are experimentally investigated with receiver shapes. Generally the heat transfer characteristics become different according to the shapes and materials of the volumetric air receiver. In order to study these effects, The experimental apparatus adopting laminated mesh and honeycombs as the volumetric air receiver is proposed. The receiver consists of laminated mesh (diameter; 100mm, thickness; 1mm), honeycombs (diameter; 100mm, thickness; 30 mm) inserted out the heat transfer characteristics of the laminated mesh the air temperatures are obtained by installing 3 thermocouples on each layer, dividing ceramic tube into 4 layers. Also, a radiative shield is installed to measure the only air temperature. The data for laminated mesh and honeycomb thickness of 30, 60, 90mm are obtained. The results show that the temperature of layer 3 is higher than those of layer 2 and layer 1.

• Journal of the Korean Wood Science and Technology
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• v.51 no.1
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• pp.14-22
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• 2023

Economical use of larix (larch) boards (grade 3) in industries is lower than that of imported hardwood; thus, studies have been conducted toward performance improvement of larix boards. Herein, flexural modulus of larix board samples laminated with wood adhesives polyurethane resins, poly (vinyl acetate) resins, phenol-resorcinol-formaldehyde resins, melamine-formaldehyde resins, and urea-formaldehyde resins was compared with that of the samples bonded with adhesives reinforced with mesh-type basalt fibers. Moreover, the flexural moduli of the laminated samples bonded by mesh-type basalt fibers were compared with those of reinforced samples. The results showed that boards laminated with polyurethane and urea-formaldehyde resin adhesives had higher flexural modulus than those without the lamination. In particular, the increase in the flexural modulus was relatively significant for the 2- and 3-ply board structures laminated with polyurethane adhesives compared to those with reinforcement. The 3-ply board structure without reinforcement had the highest flexural modulus when the urea-formaldehyde resin adhesive was used.

• Journal of the Korean Solar Energy Society
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• v.27 no.2
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• pp.71-78
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• 2007

The heat transfer characteristics of solar tower receivers are experimentally investigated with receiver shapes. Generally, these become different according to the shapes and materials of the volumetric air receiver. In order to study these effects, the apparatus adopting laminated mesh and honeycombs as the volumetric air receiver is proposed. The receiver consists of laminated mesh (diameter; 100 mm, thickness; 1 mm), honeycombs (diameter; 100 mm, thickness; 30 mm) inserted into ceramic tube (inside diameter; 100 mm, outside diameter; 120 mm, length: 1000 mm). To apply heat to the receiver, an electric heater is used. To find out the heat transfer characteristics of the laminated mesh, the air temperatures are obtained by installing 3 thermocouples on each layer, dividing ceramic tube into 4 layers. Also, a radiative shield is installed to measure the only air temperature. The data for laminated mesh and honeycomb thickness of 30, 60, 90 mm are obtained. The results show that the temperature of layer 3 is higher than those of layer 2 and layer 1.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.11
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• pp.760-766
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• 2008

The characteristics of heat transfer and pressure drop of several different porous materials which can be used as inserts inside solar volumetric air receivers were experimentally investigated. Generally, porous materials were inserted into solar volumetric air receivers to increase the thermal performance. In the present work, honeycomb (diameter: 100 mm, thickness: 30 mm), laminated mesh (diameter: 100 mm, thickness: 1 mm) are considered as the inserts for the experiment. The experimental apparatus consists mainly of a cylindrical ceramic duct as a receiver and an electric heater as an energy source. This system is an intake open loop, which used as air of working fluid. The temperatures inside the ceramic tube are measured by thermocouples, which are installed at each layer of the porous materials. The pressure-drop experimental apparatus is fabricated alike the above experimental equipment. An acrylic tube is used like as the ceramic tube, which has the same specifications of the ceramic tube. The pressure drop of porous materials inserted in the acrylic tube is measured between front and rear of those by transmitter. The results show that the laminated mesh surpasses the honeycomb of heat transfer and pressure drop increase as the porous material thickness and Reynolds number.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3389-3394
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• 2007

Characteristics of heat transfer and pressure drops of fills for solar tower volumetric air receivers are experimentally investigated with the material and the thickness. The volumetric air receiver considered in this paper consists of a ceramic tube and fills are inserted in the ceramic tube. Air is used as the working fluid. Two materials, which are a honeycomb(diameter: 100mm, thickness: 30mm) and laminated mesh(diameter: 100mm, thickness: 1mm), are considered as the fills. In order to investigate the characteristics of heat transfer of fills, this volumetric air receiver is heated by an electric heater and air temperatures in ceramic tube are measured. Also, the radiative shields are installed to measure the only air temperature. In addition, the pressure losses are measured with the thickness of fills while the air goes through the fills inserted in an acrylic tube. The flow becomes turbulent and fully developed in front of the fills. The results show that the heat transfer and pressure drop characteristics of the laminated mesh are superior to those of the honeycomb.

• Journal of the Korean Wood Science and Technology
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• v.31 no.5
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• pp.23-34
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• 2003

This study was carried out to investigate the mechanical properties of fabric E-glass fiber reinforced laminated timber. Specimens used to Korean red pine(Pinus densiflora) and Japanese larch(Larix kaemferi). Fabric E-glass fiber was inserted in the solid wood with aqueous polymer-isocyanate resin(MPU-500). The results were as follows: 1. Aqueous polymer-isocyanate resin(MPU-500) was good resin to manufacture laminated timber. specially, it was satisfied to property standard of construction laminated timber(KS F 3021) except for two ply glass fiber. 2. Bending and shear strengths of solid wood inserted with fabric glass fibers were not different from control solid wood. But, proportional limit bending stress was increased following the number of fabric glass fibers. Therefore, it was considered that to improve the bending and shear strength of fabric glass fiber reinforced laminated timber, the glass fiber thickness and its mesh should be modified to fitness following working conditions.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2001.05a
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• pp.224-227
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• 2001

Adaptive analysis of multilayered composite and sandwich plates is carried out. The adaptive analysis is based on a finite element error form, which measures the difference between the through-the-thickness distribution of finite element displacement and the actual displacement. The region where the error-measure exceeds the prescribed admitted error value, the finite element mesh locally refined in the thickness direction using the mesh superposition technique. Several numerical tests are conducted to validate the effectiveness of the current approach for adaptive analysis of laminated plates.

• Steel and Composite Structures
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• v.24 no.6
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• pp.697-709
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• 2017

The current study addresses the local buckling analysis of an infinite thin rectangular symmetrically laminated composite plate restrained by a tensionless Winkler foundation and subjected to uniform in-plane shear loading. An analytic method (i.e., one-dimensional mathematical method) is used to achieve the analytical solution estimate of the contact buckling coefficient. In addition, to study the effect of ply angle and foundation stiffness on the critical buckling coefficients for the laminated composite plates, the parametric studies are implemented. Moreover, the convergence for finite element (FE) mesh is analysed, and then the examples in the parametric study are validated by the FE analysis. The results show that the FE analysis has a good agreement with the analytical solutions. Finally, an example with the analytical solution and FE analysis is presented to demonstrate the availability and feasibility of the presented analytical method.

• Structural Engineering and Mechanics
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• v.28 no.5
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• pp.603-633
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• 2008

A four-node plate finite element for the analysis of laminated composites which is developed using strain gradient notation is presented. The element is based on a first-order shear deformation theory and on the equivalent lamina assumption. Strains and stresses can be calculated at different points through the thickness of the plate. They are averaged values due to the equivalent lamina assumption. A shear correction factor is used as the transverse shear strain is taken to be constant over the plate thickness while its actual variation is parabolic. Strain gradient notation, which is physically interpretable, allows for the detailed a-priori analysis of the finite element model. The polynomial expansions are inspected and spurious terms responsible for modeling errors are identified in the shear strains polynomial expansions. The element is corrected by simply removing the spurious terms from the shear strains expansions. The element is implemented into a FORTRAN finite element code in two versions; namely, with and without spurious terms. Results are compared to show the effects of the spurious terms on the solutions. It is also shown that a refined mesh composed of corrected elements provides solutions which approximate very well the analytical solutions, validating the procedure.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2007.04a
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• pp.133-136
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• 2007

It has been applied the self adhesion waterproofing sheet which is developed from exist asphalt waterproofing sheet by heat and torch in domestic construction field. However, the problem of waterproofing have constantly happened due to air pocket condition and defect of joint part in waterproofing construction. Therefore, in this study, we would like to analyze the field application as testing in side of materials and construction method of self adhesion butyl rubber sheet and study of the materials performance.