This research is to investigate the flow characteristics of micropump with two different types of diffuser outlet in micropump (straight and round). Four different outlet diameters(1mm, 1.5mm, 2mm at straight type of diffuser outlet and single outlet diameter(1mm) at round type are utilized for the flow analysis of the diffuser in micropump. Velocity and pressure distributions of fluid over the flow domain are numerically calculated for the shape optimum design of diffuser in micropump with uniform inlet velocity and pressure. According to the calculations of local maximum pressure at diffuser outlet, straight type of diffuser with larger diameter of diffuser outlet is of highest flow energy performance of the flow channel shapes in the present micropump.

In this study, flow characteristic of small vertical-axis wind turbine was performed to analysis the numerical analysis. Blade geometry in the wind turbine is NACA 6512-43, and various degrees of the wind turbine accelerator were adopted. Numerical models are used for the analysis with CFD program of Ansys fluent and RNG k-e turbulence model was used. Rotational speed value of the wind turbine in analysis condition were obtained by the experiment. When the wind turbine accelerator is equipped, exit velocity of wind turbine accelerator tended to increases. Also RPM of wind turbine is increase. And maximum RPM appeared that wind turbine accelerator in degree 60° is equipped.

To perform long-term sewer monitoring, It is important to understand the nature of the wastewater flow that occurs at the point on early stage of the monitor and to prevent in advance a problem which may caused. We can infer the flow properties and external factors by analyzing the scatter graph obtained from the measured data flow rate monitoring data since an field external factor affecting the sewage flow is reflected in the flow rate monitoring data. In this study, Selecting the three points having various external factors, and we Inferred the sewer flow characteristics from depth-velocity scatter graph and determined the analysis equation for the dry-weather flow rate data. At the‘point 1’expected non-pressure flow, we were able to see the drawdown effect caused by the free fall in the manhole section. At the‘point 2’, existed weir and sediments, there was backwater effect caused by them, and each of size calculated from the scatter graph analysis were 400 mm and 130 mm. At the‘Point 3’, there is specific flow pattern that is coming from flood wave propagation generated by the pump station at upstream. In common, adequate equations to explain the dry weather flow data are flume equation and modified manning equation(SS method), and the equations had compatibility for explaining the data because all of R2 values are over 0.95.

In this study, we have modeled a subsonic diffuser with rectangular prism and tried to investigate the influence of a turbulent wake flow by numerical simulation using computational fluid dynamics based on steady-state Navier-Stokes equation and standard k-ε model. A commercial CFD program, FLUENT, is used on the analysis. The turbulent wake is generated by a rectangular prism, which is installed at the diffuser. Flow Uniformity Showed the best results in the case of AR=1:1 and tended to be uniform in the critical point at Re=8.8×103

The purpose of this study is to develop the flowmeter of high viscosity paint spraying system. In this study, the numerical flow analysis of the flowmeter was performed. The velocity and the pressure distributions were obtained using the turbulent SST(Shear Stress Transport) model. The ICEM-CFD13 and CFXMesher, reliable grid generation software was also adapted to secure high quality grid necessary for the reliable analysis. According to the simulation results, the flow rate of flowmeter is 6.49l/min in case of Δp=45bar. This result was in good agreement with design result and could be applied to the actual design of the high viscosity paint spraying system

The basis of the cobalt demand analysis by use was established via the investigation and analysis of the cobalt materials flow, and the overall cobalt metal material and parts industry structure in Korea was examined to determine the cobalt material flow. The markets of the cobalt material for machinery were studied, including their interrelations, via market and study trends, and relevant plans were examined. The results of the study indicated that the advanced core technology for advanced industry and technology-intensive industry development is required to structurally innovate the parts materials and basic materials industries and to upgrade the catch-up industry structure to the new frontier structure.

This study is done as a comparison analysis on existing studies on analysis and interpretations of solenoids. When there is no power in a solenoid valve, a flow passage is formed from a pressurized ports, Pc, to Ps, which are connected to a crankcase of a pressurizer. An inlet to Pc port is varied in three different sizes: 3.8 ㎜(Type-1), 4.0 ㎜(Type-2) and 4.2 ㎜(Type-3). It is determined that there will be changes in coolant flow into the solenoid valve and the flow properties from Pc port to Ps port are compared and analyzed. As the results, the flow demonstrates the maximum speed of 500 ㎧, 46 ㎧ and 433 ㎧ with 0.2 ㎫ for the inflow pressure and the maximum speed of 1400 ㎧, 129 ㎧ and 1200 ㎧ with 1.5 ㎫ for the inflow pressure.

This paper carried out a comparative analysis with papers on the analysis and analytic research of conventional solenoid. In case the current of solenoid valve is cut off, a flow path is formed from pressure port (Pc) connected with the crankcase of compressor to Ps port. At this time, the size of Pc port hole was so adjusted (Type-2) that it was smaller than 4.0mm(Type-1) of original hole by 0.2mm. After that, it was thought that an effect would be produced on the flow change of refrigerant which came into the solenoid vale, therefore the flow characteristics in moving from Pc port to Ps port was predicted and comparatively analyzed. According to the results of flow analysis, a velocity of approximately 46m/s and 129m/s was shown at the maximum in case of 0.2 and 1.5 MPa in Type-1, and the maximum velocity of approximately 500m/s and 1400m/s was shown in case of Type-2.

In the paper an efficient numerical algorithm to predict the flow phenomena around the water-jet propulsion system was described. The potential-based flow analysis method was adopted to predict the velocity and the pressure on the inlet duct of the water-jet propulsion system. The method employed normal dipoles and source distributed on the solid surface such as the inlet duct and the tracked vehicle. The inlet duct and outlet open boundary surfaces were introduced where the sources and dipoles were distributed to define a closed boundary surface. The developed numerical algorithm was applied to a tracked vehicle propelled by the water-jet propulsion system with the different IVR(inlet velocity ratio). The results by the numerical analysis were compared with the experimental data in order to verify the feasibility of the proposed numerical algorithm.

A numerical analysis was performed to study PEMFC performance characteristics depending on the flow direction of cathode reactant gas, cathode relative humidity, and porosity of gas diffusion layer. As cathode relative humidity decreases and porosity increases, current density increases due to better diffusion of reactant gas to cathode surface. As current density increases, power density increases initially and then decreases with its maximum located around current density value of 2.2 Amperes per square centimeter. From the analysis of current density distribution inside membrane, the counter-flow cases show more uniform profile across the membrane than the co-flow cases due to more uniform reactant gas supply.

A 2D axisymmetric numerical analysis was performed to study the characteristics of charge process inside solar thermal storage tank. The porosity and heat transfer coefficient of filler material as well as inlet velocity of heat transfer fluid are selected as simulation parameters. The porosity is varied as 0.2, 0.5, and 0.8 to account for the effect of filler granule geometry. Two levels of the heat transfer coefficient is adopted to assess the heat transfer between heat transfer fluid and filler material. The inlet velocity is varied as 0.00278, 0.0278, and 0.278m/s. As both of the porosity and the heat transfer coefficient increase, the discrepancy of the temperature distributions between the filler and heat transfer fluid decreases. As the inlet velocity increases, the penetration depth of the heat transfer fluid increases proportionally.

A 2D axisymmetric numerical analysis was performed to study the characteristics of charge process inside solar thermal storage tank. The interfacial area density and inertial resistance of filler material are selected as simulation parameters. The interfacial area density is varied as 800, 2000, and 4000 1/m. The inertial resistance is varied as 1, 3, and 5 1/m. When the interfacial area density increases from 800 to 4000 1/m, the discrepancy of the temperature distributions between the filler and heat transfer fluid decreases. As inertial resistance increases from 1 to 5, both of the temperature and fluid flow pattern changes considerably.

Numerical analysis of the electric vehicle battery was performed for the optimization of the thermal management under various operating conditions. For the analysis of internal flow and temperature distributions under the different operating conditions of battery, the battery system which was packed 18 battery cell with -25℃∼ 65℃ operating temperature range was considered, and the air flow rate, velocity, and ambient temperature conditions were varied and compared. It was revealed that the cooling system for battery was necessary to maintain its performance for hot ambient conditions. Especially, in this condition, at least 90m3/h of air flow rate are required to maintain the module temperature under 40℃. However, heating system of battery for cold ambient conditions doesn't need.

In recent years, accident induced by human error is increasing in the chemical plant. Human error analysis of the chemical plant was conducted on the basis of past accident. Some company called by A for the basis of a chemical accident. Factor analysis of human errors was separated in plant operation and work. Agency's work of occupational safety & health was classified into four types. It is based on the work before, during work, recovery work, and discontinue work. It was still separated work of human error by analysis and then was derived factor and issue. The human error factor and priority for accident prevention in the chemical plant is presented.

The hydrofoil-tip mixer can be used to create the desired material by mixing the two materials in various industries, especially in the waste water and sewage water treatment. The purpose of this study is to clarify flow characteristics induced by 3 types impellers in a mixing tank by CFD. In this study, flat plate, hydrofoil and hydrofoil-tip type impellers are used and the rotating speeds of impellers are 25, 35, 45 rpm. The results in present study show that hydrofoil-tip type is the most proper impeller for mixing in the waster water treatment tank and reducing required power of rotating impeller. This results can be used for the design of the mixing tank in the waste water treatment system.