• The KSFM Journal of Fluid Machinery
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• v.15 no.5
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• pp.5-10
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• 2012

An experimental test facility for the complete characteristics of pumps is constructed at KIMM(Korea Institute of Machinery and Materials). All sensors instrumented in test facility for measuring flow rate, pressure, force and moment are in-situ calibrated by primary method. This paper describes the test facility and test technique of the complete characteristics of pumps, together with an experimental test results for a reactor coolant pump which is designed at KIMM for the first time in Korea. The test results for the mixed-flow type pump of $n_s$=1.425 are presented by three curves: constant head, torque, and speed.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.9
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• pp.791-801
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• 2000

An experimental study was conducted to analyze the effects of oil on refrigerant flow through adiabatic capillary tubes, and to develop a model for mass flow rates of refrigerant/oil mixture at various capillary tubes and flow conditions. Mass flow rates and the profiles of the pressures and temperatures along the capillary tubes was obtained with the oil concentration of R-22/SUNISO 4GS oil mixture at various test conditions. The flow trends as a function of geometry and flow conditions for pure refrigerant and refrigerant/oil mixture were similar in adiabatic capillary tubes. Mass flow rate of the refrigerant/oil mixture was less than that of pure refrigerant at the same test conditions.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.5
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• pp.403-408
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• 2012

In this paper, we propose useful load flow algorithms called FEDL (fast enhanced decoupled load flow). The proposed load flow method can improve the convergence characteristics particularly when the P-Q coupling becomes significant and the power system operating states deviate from the conditions required for stable convergence of the FDL by reflecting in part the effects of the off-diagonal terms in the Jacobian. In our test with IEEE AEP-30 bus system and RTS-96 73-bus system, it converge even when the fast decoupled load flow (FDL) and its variations keeping load flow matrices constant experience convergence problems. Test results show promising performances of the proposed algorithms in their convergence characteristics both in number of iterations and overall convergence speeds.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.7
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• pp.66-75
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• 1999

Many researchers have developed the measurement technique of in-cylinder flow. Recently, there are lots of studies on steady flow with different SCV geometries. In this study the flow characteristics of four-valve cylinder head were examined in a steady test rig for different SCV open ratios. Each swirl ratio of several SCV angle was quantified by swirl impulse meter and 2D-LDV measurement. The results showed that the swirl ratio was controlled between 2.3 and 3.8 based on SCV angles. The velocity distributions of in-cylinder flow field were measured by 2-D LDV test and visualized swirl and tumble flow pattern at different positions. In this engine , we found out that the swirl was dominant flow.

• Transactions of The Korea Fluid Power Systems Society
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• v.3 no.1
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• pp.15-19
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• 2006

In this study, a measurement method of leakage flow-rate for pneumatic driving apparatus is proposed. The existing measurement methods of leakage flow-rate of air need disassemble the test component. Therefore, there is no effective method to measure the leakage flow-rate while operating pneumatic driving apparatus. In this study, the leakage flow-rate is measure from the pressure change in an isothermal chamber that can realize isothermal conditions by stuffing steel wool into it. Therefore, wide range of flow-rate could be measured only from the pressure response and the leakage flow-rate can be measured during operating pneumatic driving apparatus. The effectiveness of the proposed method is proved by experimental results.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.05a
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• pp.61-64
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• 2008

For the performance evaluation of liquid mono-propellant thruster, Vacuum Hot-fire test is necessarily required. An accurate flow measurement is one of the key parameters to the successful T&E program. This paper describes the characteristics of the coriolis flowmeter, explains the cold-flow test using simulant propellant (DIW), and presents the test results. Finally, the cold test results have been verified in comparison with the hot-fire test data.

• Transactions of Materials Processing
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• v.18 no.8
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• pp.640-645
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• 2009

Recently, boss and rib test based on backward extrusion process was proposed to quantitatively evaluate the interfacial friction condition in bulk forming process. In this test, the tube-shaped punch with hole pressurizes the workpiece so that the boss and rib are formed along the hole and outer surface of the punch. It was experimentally and numerically revealed that the height of boss is higher than that of the rib under the severe friction condition. This work is focused on the effect of the punch design and flow stress on deformation pattern in boss and rib test. From the boss and rib test simulations, it was found that there is slight variation in both the heights of boss and rib according to the length of punch land, nose radius, and face angle. However the hole diameter of the punch and the clearance between the punch and die have a significant influence on the calibration curves showing the heights of the boss and rib. In addition, the effect of flow stress on the calibration curves was investigated through FE simulations. It was found that there is no effect of strength coefficient of the workpiece on the calibration curves for estimation of friction condition. On the other hand, the strain-hardening exponent of the workpiece has a significant influence on the calibration curve.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.444-447
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• 2008

A nuclear fuel test loop (after below, FTL) is installed in IR1 of an irradiation hole in HANARO for testing neutron irradiation characteristics and thermo hydraulic characteristics of a fuel loaded in a light water power reactor (PWR) or a heavy water power reactor (CANDU). There is an in-pile section (IPS) and an out-pile section (OPS) in this test loop. When HANARO is normally operated, the fuel loaded in the IPS has a nuclear reaction heat generated by a neutron irradiation. To remove the generated heat and to maintain an operation condition of the test fuel, a main cooling water system (MCWS) is installed in the OPS of the FTL. The pump can not continuously suck a fluid and not pressurize the fluid during a cold function test. To verify the flow characteristics of the MCWS, a flow net work analysis has been conducted. When the higher elevation pipelines wholly filled with coolant, it was confirmed through the analysis results that the pump pressurized the coolant normally. And the analysis results described the system characteristics with operation temperature and pressure variation satisfactorily.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.61-65
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• 2010

To research and develop a liquid rocket engine injector, it needs empirical studies about the hydrodynamic and spray characteristics such as pressure drop, mixing and atomization. In this study, the design and implementation of lab-scale cold-flow/hot fire test stand which can supply cryogenic propellant and be controlled by time-critical LabVIEW cyclogram logic has been done. In order to visualize the spray of a liquid-centered swirl coaxial injector in cryogenic condition, LN2-GN2 cold-flow test has been done, and combustor assembly and thrust bed for LOX-$GCH_4$ hot-fire test have been fabricated.

• Journal of Mechanical Science and Technology
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• v.17 no.10
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• pp.1520-1532
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• 2003

An experiment was performed to obtain the local heat transfer coefficient and Nusselt number in a circular duct with a 180$^{\circ}$ bend for Re=6 x 10$^4$, 8 x 10$^4$ and 1 x 10$\^$5/ under swirling flow and non-swirling flow conditions. The test tube with a circular section was made from stainless steel having a curvature ration of 9.4. Current heat flux of 5.11 kW/㎡ was applied to the test tube by electrical power and the swirling motion of air was produced by a tangential inlet to the pipe axis at 180$^{\circ}$. Measurements of local wall temperatures and the bulk mean temperatures of air were made at four circumferential positions at 16 stations. The wall temperatures showed a reduced distribution curve at the bend for the non-swirling flow, but this effect did not appear for the swirling flow. The Nusselt number distributions for the swirling flow, which was calculated from the measured wall and the bulk temperatures, were higher than that of the non-swirling flow. The average Nusselt number of the swirling flow increased by about 90-100%, compared to that of the non-swirling flow. The Nu/Nu$\_$DB/ values at the 90$^{\circ}$ station for non-swirling flow and swirling flow were approximately 2.5 and 4.8 at Re=6x10$^4$ respectively. The values agree well with Said's results for non-swirling flow.