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[en] In present study, the effect of dimples on the flow and the heat transfer between two plate-fins with dimples was numerically analyzed with Reynolds numbers from 150 to 2000. The dimples were applied to extend the fin surface area and to promote turbulent flow around plate-fins. The relatively strong vortices were generated in dimples and it enhanced heat transfer of plate-fins.
[en] In this study, we investigated the hydrodynamic and thermal performance of constructal architectures based on the mass flow rates for the given pressure drop and identify the required pumping power and thermal resistance. The five flow configurations described in this paper are the first, second constructs with optimized hydraulic diameters and nonoptimized hydraulic diameter, respectively, including the serpentine configuration. The results suggest that best fluid flow structure is the second constructal structure with optimized constructal configurations. We also found that the optimized structure of cooling plates could enhance heat transfer remarkably and decrease pumping power dramatically compared with the traditional channels.
[en] In this paper, welding residual stresses for butt weld of thin-walled plate are calculated based on 3- dimensional finite element analyses. To study the effect of mechanical boundary condition on welding residual stresses, various boundary conditions are considered. Predicted welding residual stresses are validated existing results of measurements and finite element analyses and compared with welding residual stress profile in the R6 code. The results of this work are expected to be used in assessment of the crack in weldment.
[en] Numerical simulation is performed for liquid flow on a micro-structured hydrophobic surface, where liquid slip occurs due to the gas existing between the surface structures. The liquid-gas interface is calculated by a level-set method which is improved by employing a sharp-interface technique for accurately enforcing the no-slip and contact angle conditions at the fluid-solid interface as well as the velocity and stress matching conditions at the liquid-gas interface. The numerical results show that the liquid flow and friction reduction depend strongly on the contact angle, the gas-solid area ratio and the geometric parameters of microstructure.
[en] This proceedings contains articles of the KSME 2009 fall annual meeting. It was held on 4-6 Nov, 2009 in Pyeongchang, Korea. This proceedings is comprised of 10 sessions. The main subject titles of session are as follows: materials and fracture mechanics, CAE and applied mechanics, dynamics and control, fabrication and design, reliability, biotechnology, micro/nano-mechanics, thermodynamics, fluid mechanics, energy and dynamics. (Yi, J. H.)
[en] The thermal process of wastes with higher calorific value by pyrolysis is reviewed to recover the value added three by-products; a pyrolytic char, a pyrolytic oil, and a non-condensable gas. These by-products from pyrolysis of the waste is converted for electricity power and thermal energy thru gasification process as well as waste heat recovery process. The energy resource and several processes in the integrated pyrolysis gasification combined cycle for waste treatment are investigated with the conceptual design in using the obtained operation data from the pyrolysis pilot, demonstration and commercial plant.
[en] Although the pipe bend is the most commonly used component in pipeline system, useful assessment solutions for stress intensity factor of pipe bends are not exist. This paper shows the trend of the stress intensity factor for pipe bends with through-walled crack under internal pressure based on the FE analysis. The trend is different from existing solutions of straight pipe.
[en] This paper presents plastic limit loads for thick-walled pipes where the mean radius-to-thickness ratio is less than five. In terms of crack geometry, axial and circumferential surface cracks are considered, together with limiting through-wall crack cases. In terms of loading, internal pressure, axial tension and global bending are considered.
[en] The technology of ISO Solenoid Valves is now considered as a core technology in the fields of the production line of semi-conductor chips and the ISO fluid chips for medical applications. And ISO Solenoid Valves, which operate by compressed air, are characterized by high speed response, great repeatability and that the pressure on the cross sectional area of poppet is kept constant regardless of the fluctuation of the pressure exerted on the ports. The primary objective of this study is to compare the optimally designed Solenoid Valve with the actually produced one and to design a power saving circuit which can highly improve the efficiency by providing optimal current according to mechanical load.
[en] SMART has been developed as an environment-friendly reactor that gives freshwater from the sea as well as electric power. This paper presents the modal analysis prior to evaluating the structural safety against the seismic load. A finite element model of the reactor vessel and the internal structures has been simplified and a modal analysis has been performed using ANSYS. The simplified model is composed of beam elements for the reactor vessel and lumped-mass elements for the internal structures.