[en] Effects of essential geometric and operating factors controlling steady evacuation performance and transient operating characteristics of a straight axi-symmetric Supersonic Exhaust Diffuser (SED) with zerosecondary flows are studied experimentally and numerically. Pressure records along diffuser wall and in vacuum chamber are measured by a small-scale cold gas simulator using cold nitrogen gas as a working fluid. Preconditioned Favre-Averaged Navier-Stokes equations with low Reynolds number κ-ε turbulence model edited for turbulence compressibility effects are employed to solve steady and unsteady diffuser flows

[en] This paper presents the theoretical results of a detailed investigation carried out into the plastic bending collapse behaviour of circular pipe. To predict the plastic energy dissipation during the deformation of circular pipe on the mid-section, a new mode of collapse mechanism is suggested. A modified plastic collapse analysis adapting upper bound technique and moving plastic hinge solution based on an existing deformation mechanism model was considered. This study shows clearly that the new mode of collapse mechanism suggested gives more closer to that of the practical collapse mechanism

[en] In this study, We simulate mixing phenomena by collision of two nanofluids in very narrow solid channel which has a Face-Centered-Cubic(FCC) structure. It is not trivial to transport fluids around inside the Nano-Electro-Mechanical- Systems(NEMS) such as biofluidic chips. Also, reactive fluids must be brought together and mixed. We do this by performing molecular dynamics simulation and we find the fact that mixing efficiency is largely dependent to convective velocity of fluid and channel temperature

[en] This proceedings contains articles of the KSME 2007 fall annual meeting. It was held on Oct 31-Nov 2, 2007 in Pyeongchang, Korea. This proceedings is comprised of 8 sessions. The main subject titles of session are as follows: materials and fracture mechanics, dynamics and remote control, CAE and applied mechanics, fabrication and design engineering, fluid mechanics, reliability engineering, energy and power engineering, thermodynamics engineering. (Yi, J. H.)

[en] In this paper, we researched flow of 8000 ∼ 24000 Reynolds number around a blade model of Savonius-type wind turbine with experimental and numerical method. For the blade shape of arc, we analyzed flowfield with streak-image flow visualization, measured wake, computed drag coefficients, and compared them for given angle of attacks. The result of research can be used to design aerodynamic performance of Savonius-type turbine rotor directly

[en] Thermal barrier coating system for gas turbine blade were thermally aged by isothermal heating in the furnace varing aging time and temperature. Then, micro Vickers hardness test was done for the cross section of bond coat and Ni-based superalloy substrate. Also, the thickness of TGO was measured by image analyzer and the changes in the microstructure and element distributions in the coating were analyzed by optical microscope and SEM-EDX analysis. No significant changes in the Vickers hardness of the bond coat were observed as the coated specimen was aged at high temperature and delaminations near between top coat and bond coat occurred when the coatings were aged for 50 hr at over 1,151 .deg. C

[en] Shock tubes are devices in which the state of a gas is changed suddenly from one uniform state to another by the passage of shock and expansion waves. In the theory of ideal shock tube flow, it is customarily assumed plane wave. However, such waves are generally not centered, or may not even by plane in practice. In the present research, the numerical and experimental studies were carried out in order to investigate the effect of the diaphragm rupture process on the flow characteristics of expansion and shock waves generated near the diaphragm using dried cellophane

[en] Numerical calculations have been carried out to investigate the effect of traveling magnetic field on the liquid steel flow in a continuous casting mold. It is a general procedure to add Lorentz force as a source term in momentum equation for steady state equations. However, in using traveling magnetic field, the changing magnetic field cannot be counted at steady state calculation. It has been in question if the steady state calculation results are in agreement with the one by unsteady state calculation. In this study, the steady state calculation is improved by utilizing new average Lorentz force value

[en] The optimal dimension design of core tube inside of bubble pump is presented. The flow regime in this study is vertical tube slug flow. In order to get the optimal performance of bubbles to lift the liquor, by the help of which a target pressure difference was produced for the circulations of working fluid in the system, the analysis both from experiment result and theoretical model were included to design the length and diameter of the core tube in this paper. Additionally, the finally working condition especially the pressure was given to evaluate the optimal design

[en] This paper proposes closed-form plastic limit load solutions for elbow with circumferential through-wall crack or part-through surface crack under internal pressure. This work was performed using 3-dimensional, small strain FE analyses based on elastic-perfectly plastic materials. The wide range of elbow and through-wall crack (or part-through surface crack) geometries is considered. Circumferential crack in extrados and intrados is considered