• Journal of Korean Society of Environmental Engineers
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• v.27 no.7
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• pp.726-731
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• 2005

Sedimentation is treated as the most important unit process in waterworks, and plays great role on turbidity removal efficiency. Rectangle sedimentation basin is the most widely accepted sedimentation process. But it has some problems with short-circuit flow and density flow caused by temperature and influent turbidity variation. To solve these problems, installation of rectification wall was suggested, but not generally fully accepted in field. Because hole of rectification wall cause jet flow. In this research, use of moving baffle was investigated. Moving baffle was designed to induce uniform velocity at every section of water flow. The baffle walls was made from soft fiber materials. The baffle walls with flow of sedimentation basin moves at same speed. It is like that it controls density flow and short-circuit flow and induce uniform velocity at every section of water flow in sedimentation basin. When moving baffle was operated retention time of sedimentation basin was extended to 1 hours. When it talked again and the effluent time of highest concentration of the chlorine ion from 100 minutes was extended to 160 minutes. Turbidity removal efficiency was tested with different operation modes(continuous and batch) with influent turbidity and retention time. It was revealed that turbidity removal efficiency carl be improved up to 36%(continuous mode) and 58%(batch mode) respectively. Consequently if moving baffle introduces in Rectangle sedimentation basin, it forecasts that the turbidity improvement above 30% will be possible.

• Journal of the Korean Society of Propulsion Engineers
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• v.6 no.4
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• pp.47-58
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• 2002

The pressure regulator has been developed as a pressure-control device of propellant tank in KSR-III. The pressurization system of KSR-III is a basic pressurization system composed of pressurant, He tank and propellant tank. The pressure-control regulator is the most important part of gas-pressurized feed system along with He tank, pyrovalve and He fill valve. The first model of the regulator is tested to satisfy in leakage, strength and basic performance. The second model is tested in the overall test of the KSR-III propulsion system using water. From the test result of the second model, we conclude that the capacity of valve(Cv) must be increased in real system. The third model is modified and tested in the overall test of KSR-III propulsion system using propellant. Finally, the pressure-control regulator is qualified from firing test.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.3
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• pp.89-95
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• 2015

Performance test was conducted for an oxidizer pump and a fuel pump for a 7 ton class rocket engine, by using water. The pumps were driven by an electric motor. The hydrodynamic performance and the suction performance were measured at flow ratio of the design and off-design conditions. Head-flow curve, efficiency-flow curve, and head-cavitation number curve were obtained. It is confirmed that the pumps can satisfy the design requirements of hydrodynamic performance in terms of the head and the efficiency. The pumps also satisfied the design requirements of suction performance.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.4
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• pp.18-23
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• 2018

For the control of pre-burner combustion pressure, the open angle of the TTR (Throttle for Thrust Regulation) valve was varied from $143^{\circ}$ to $185^{\circ}$ while testing cold flow, ignition, and combustion. The major performance variables of rocket engines and hydraulic performance of the TTR valve regarding the open angle were verified. However, the controllability of pre-burner combustion pressure was not verified due to the limitations of the test. Comprehensive research will be done after addressing these problems.

• The KSFM Journal of Fluid Machinery
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• v.14 no.1
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• pp.61-65
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• 2011

A series of water tests of a fuel pump for liquid rocket engines are performed at a room temperature. According to the test results, the head coefficient of the pump follows the conventional similarity rule - unlike this, the pump shows better efficiency with higher rotational speed. Also, it is found that the pressure at the rear bearing outlet is higher than expected because the inlet of bypass pipe line is narrow. Furthermore, the cavitation performance of the fuel pump is found to be sufficient for the engine operation and is better at the lower flow ratio and higher rotational speed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.111-114
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• 2009

A catalyst ignitor of small thrust engine using hydrogen peroxide and kerosene was designed and fabricated, which confirmed mass flow rate for design pressure through the water cold-flow test in this study. In order to investigate ignition performance, it was changed that mixture ratio for kerosene mass flow rate in a position which heat of hydrogen peroxide decomposition comes to a steady state. And we confirmed stable ignition property in a wide range of mixture ratio.

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.523-526
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• 2006

A series of hydraulic and cavitation tests are performed in water environment in order to verify the hydraulic and cavitation performance of three types of LOX pumps. All the performances of the pumps are found to be satisfied with each design requirement. In the hydraulic tests, the head and efficiency are increased as the gap between floating ring seals and the impeller shoulder is decreased. In the cavitation tests, some pumps show decrease in the cavitation performance as the flowrate of the pump is decreased.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.104-105
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• 2012

The design of coaxial porous injector was suggested to improve the mixing and atomizing performance at the center region of the conventional 2-phase flow coaxial shear injector spray. Several cold flow tests of 2-dimensional injectors was performed, and the gas injection area was varied to determine the effect of the magnitude of gas radial momentum.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2005.11a
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• pp.358-362
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• 2005

An effective control of the axial thrust of a turbopump is one of the critical issues for its operational stability. In order to assure the stability of a turbopump-type fuel pump for a liquid rocket engine, an axial thrust measurement system was developed and a series of axial thrust tests were performed in water environment. In the tests, the axial thrust of the fuel pump at the design flowrate satisfied the axial force condition of the bearing of the pump. Also, it was found that by using orifices with different geometries in the secondary flow passage the overall axial thrust of the pump could be controlled.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.81-84
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• 2010

In this study, a coaxial swirl injector using hydrogen peroxide and kerosene was designed and combustion performance tests were performed to evaluate combustion characteristic according to mixture ratio. Spray characteristic of the injector was verified by cold flow test and combustion performances according to mixture ratio were evaluated by the characteristic exhaust velocity. Test results showed that the combustion efficiency at the design condition was about 95% and the pressure fluctuation was very small.