• Tribology and Lubricants
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• v.12 no.2
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• pp.20-31
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• 1996

Pressures in compression pockets consists of two identical spiral scrolls are influenced by gas flow resistance in discharge process and leakages in radial and tangential directions between two scroll wraps. In this paper, considering geometrical characteristics of these members, flow resistance and refrigerant gas leakage losses, pressure variations in compression pockets are calculated. For a scroll compressor model with fixed crank mechanism, acting load on crankshaft is analyzed. And, for a vertical type crankshaft-journal bearing system used in scroll compressor, nonlinear transient response is calculated including nonlinear fluid film reaction forces of journal bearings.

• Journal of the Korean Wood Science and Technology
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• v.33 no.2 s.130
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• pp.17-23
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• 2005

Juvenile and transitional-juvenile wood samples from loblolly pine (Pinus taeda) were immersed in water to investigate longitudinal and tangential swelling properties. Increment cores from twenty-six loblolly pine trees were sampled at breast height (1.37 m). Earlywood rings 5 and 9 were separated from the core, extracted, oven-dried and immersed in water at room temperature. The variance in longitudinal swell was significant for ring 5 compared to ring 9 (p = 0.001). It was found that tangential swell might predict longitudinal swelling of juvenile wood at ring 9 but not at ring 5. Poor correlation in ring 5 suggests that swelling response in younger juvenile wood may differ. The swell response at ring 5 did not follow the shrinkage models discussed in the literature while ring 9 adhered to the expected curve.

• Journal of the Korean Wood Science and Technology
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• v.19 no.4
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• pp.27-33
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• 1991

Three kinds of specimens(radiata pine sapwood, radiata pine heartwood and whemlock heartwood) were dried at four temperature levels (30, 40, 50 and $60^{\circ}C$) in an emvironmental chamber. Unsteady-state diffusion coefficients were calculated from obtained drying fates by using infinite slab equation for first half of sorption and interval diffusion equation for second half of sorption. Activation energies for moisture diffusion in wood were calculated from the diffusion coefficients obtained at four temperatures. In most cases diffusion coefficients for radial movement were higher than those for tangential movement. Activation energy differences between sapwood and heartwood weren't significant for radial movement, but were significant for tangential movement. Most activation energies calculated from drying rates were lower than heat of water condensation(about 11,000cal/mole). Specially the avenge activation energy for sapwood tangential movement was only 5,000cal/mole.

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.2
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• pp.179-190
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• 2000

The main object of this study was to investigate experimentally the characteristics of electrostatic cyclone-bag filter with upper tangential inlet in order to overcome the low collection efficiency for the submicron particle and high pressure drop which were main problems of general fabric bag filters. The experiment was carried out for the analysis of collection efficiency and pressure drop of electrostatic cyclone-bag filter comparing to those of fabric bag filter with various experimental parameters such as the inlet velocity(filtration velocity) and applied voltage etc. In the results the upper tangential inlet type showed higher collection efficiency for submicron particles below 2 ${\mu}{\textrm}{m}$ in diameter than that of center inlet and over 99.9% for overall collection efficiency. Pressure drop reduction ratios were shown as 40-50% for the applied voltage 0kV by centrifugal force and 70-90% for 20k V by the centrifuga and electrostatic force with the tangential inlet velocity (12-21m/s)

• Journal of Power System Engineering
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• v.4 no.4
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• pp.65-69
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• 2000

On the dynamic behavior of a simple beam subjected to an uniformly distributed tangential follower force, the influences of the velocities and magnitudes of a moving mass have been studied by numerical method. The instant amplitude of a simple beam is calculated and analyzed for each position of the moving mass represented by the time functions. The uniformly distributed tangential follower force is considered within its critical value of a simple beam, and four values of velocity is also chosen. Their coupling effects on the deflections of a simple beam are inspected too. When a moving mass moves after middle zone of a simple beam at the low velocities, its deflection is increased by the coupling of an uniformly distributed tangential follower force and moving mass.

• Journal of the Korean Society of Safety
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• v.29 no.3
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• pp.64-71
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• 2014

The generalized tangential stiffness matrix of semi-rigid frame element with shear deformations based on Haringx's shear theory is newly derived and compared with the previous study based on Engesser's shear theory. Also, linearized elastic and geometric stiffness matrices are newly presented from the exact tangential stiffness matrix. In oder to obtain the inelastic system buckling load of shear flexible semi-rigid frame structure, the Ef method by tangential modulus theory is adopted and the FE analysis programs are developed. Finally, the shear and semi-rigid effects of system bucking are investigated by two numerical examples.

• 한국연소학회:학술대회논문집
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• 2015.12a
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• pp.69-72
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• 2015

Computational fluid dynamics (CFD) modeling of large-scale coal-fired boilers requires a complicated set of flow, heat transfer and combustion process models based on different degrees of simplification. This study investigates the influence of coal devolatilization, char conversion and turbulent gas reaction models in CFD for a tangential-firing boiler at 500MWe capacity. Devolatilization model is found out not significant on the overall results, when the kinetic rates and the composition of volatiles were varied. In contrast, the turbulence mixing rate influenced significantly on the gas reaction rates, temperature, and heat transfer rate on the wall. The influence of char conversion by the unreacted core shrinking model (UCSM) and the 1st-order global rate model was not significant, but the unburned carbon concentration was predicted in details by the UCSM. Overall, the effects of the selected models were found similar with previous study for a wall-firing boiler.

• Nuclear Engineering and Technology
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• v.50 no.3
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• pp.425-431
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• 2018

Different methods of axial and tangential testing and various sample geometries were investigated, and new test geometries were designed to determine the ultimate tensile strength of zirconium cladding tubes. The finite element method was used to model the tensile tests, and the results of the simulations were evaluated. Axial and tangential tensile tests were performed on as-received and machined fuel cladding tube samples of both E110 and E110G Russian zirconium alloys at room temperature to compare their ultimate tensile strengths and the different sample preparation methods.

• Journal of the Korean Wood Science and Technology
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• v.9 no.3
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• pp.1-6
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• 1981

This study examined the radial variations in element demensions of mongolian oak (Quercus mongolica.), elm (Ulmus japonica.), maackia(Maackia amurensis.), castor aralia (Kalopanax pictus.) from pith outwards. Disks were cut from the d.b.h.(above 1.2m) of each species and specimen for tangential pore diameters, fiber length, ray height and width were taken from 1-3rd, 5th, 10th, 15th.............40th ring number from pith. The tangential pore diameters in the earlywood increased rapidly near the pith and then maintained almost constant or very gradually increased diameters in about 20th-30th ring number from pith. In the latewood, tangential pore diameters gradually increased from pith to outwards though the increment is smaller than in early wood. Radial variations of ray height and width maintained almost constant, gradually increased or rapidly increased diameters and then maintained almost constant from pith to outwards. Patterns of radial variations in the fiber length were almost coincident with patterns of earlywood pore diameters, and of ray height or width in Ulmus japonica and Maackia amurensis.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.2
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• pp.190-196
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• 1993

Internal high speed grinding under several high grinding wheel speed condition has been performed in this study for the effects have analyzed and compared with the grinding power, grinding tangential force and accuracy of surface with the carbon tool steel(SK3). The following results have been obtained: (1) Under the workpiece speed constant condition, increasing the grinding speed, the tangential force is decreased, and on the contrary, accuracy of surface is improved. (2) Under the speed ratio (V$_{w}$/V$_{s}$) contant condition it is possible to increase the high machining efficiency constraint to tangential grinding force constant.ant.