• Journal of the Society of Naval Architects of Korea
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• v.34 no.1
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• pp.50-59
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• 1997

Shipbuilder checks the status of main engine and propeller operation before sea trial. Generally these tests are carried out at a quay during fitting out of the ship. For these tests the operator has to estimate the maximum RPM with permissible torque and thrust to ensure the safety of the mooring line and ship. In this paper, the propeller characteristics according to the draft variation for a moored ship is inveatigated. From these tests, it is shown that shaft submergence is a dominant parameter in the propeller performance at shallow shaft submergence and that the propeller performance is dependent upon the propeller RPM when the shaft submergence is kept unchanged. In this study, a simple formula of the required thrust for a given propeller shaft submergence and propeller RPM is derived. 1be propeller thrust, which is calculated by another formula in case of dtep draft, is compared with results of bollard pull test for FPSO.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.4
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• pp.562-569
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• 1997

The axial position of an impeller is misaligned in the process of manufacturing and assembling. For a single suction centrifugal pump with balancing holes, the effect of axial displacement of impeller on the performance, leakage loss and axial thrust acting on the impeller is experimentally investigated. The axial displacement decreases the pump efficiency, increases the leakage through the clearance between wearing ring and impeller, and affects the characteristics of axial thrust.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.572-582
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• 2017

It is definitely important to measure thrust during ground test when developing air-breathing engine, and in case of air-breathing engine, gross thrust should be calculated considering not only the measured thrust but also the force induced by the air flow of engine intake. Also, side thrust like yaw and pitch should be measured and analyzed using multi-component thrust measurement system. Engine performance was accurately evaluated by calculating the gross thrust of air breathing engine precisely which is analyzed from below serial procedure: labyrinth seal isolation, 1-axis gross thrust calculation, develop multi-component thrust measurement system, and side thrust analysis.

• Journal of the Korea Convergence Society
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• v.6 no.6
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• pp.279-284
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• 2015

The vibration happened at the revolution movement of driving shaft driven with the thrust of airplane affects the great influence on the life of the shaft. And a great loss of life is caused when the fatigue damage is occurred at the driving shaft during revolution. The chattering is occurred at the driving shaft placed at the various revolution due to the aviation environment. Therefore, the part of the driving shaft concerned about the fatigue damage is grasped through the analysis study in this paper. So, the durability to prevent damage can be improved and it is possible to be grafted onto the convergence technique on the basis of a recent safe design and show the esthetic sense.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.05a
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• pp.141-144
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• 2008

Atomization characteristics and spatial distribution of the spray emanating from an injector of liquid-propellant thruster are investigated by using dual-mode phase Doppler anemometry (DPDA). Spray characteristic parameters such as the mean velocity, Sauter mean diameter (SMD), and velocity fluctuation are measured at various locations along the spray axis as well as on the radial direction. Those data are quantified in radial profile and also used to scrutinize the correlation between diameter and turbulence intensity of spray droplets. For the better visual grasp, dynamic behavior of spray droplets along the spray stream is presented through the velocity vectors projected on the plane of geometric axis of nozzle orifice and radial coordinate.

• Aerospace Engineering and Technology
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• v.3 no.2
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• pp.183-190
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• 2004

The performance analysis of a fuel pump for a liquid rocket engine has been performed numerically on its design condition. A commercial three-dimensional Navier-Stokes flow solver has been used for the computation. All of the fuel pump components - inducer, impeller, volute and secondary flow passages - are included in computation for the accurate estimation of the leakage flow rate which affects the performance and axial thrust. A pitchwise-averaged mixing plane method was used on the boundaries among the fuel pump components to save computational time. The predicted overall performance satisfied the design requirement. However, the axial thrust exceeded a permissible limit. In order to reduce the axial thrust, the secondary flow passage design has been changed. With this change, the axial thrust level has been reduced to 30% as compared with the original value.

• The KSFM Journal of Fluid Machinery
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• v.15 no.6
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• pp.46-50
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• 2012

A high-speed centrifugal pump requires more attention to the control of its axial thrust due to the high discharge pressure than a conventional industrial pump. Vanes employed toward the rear cavity of the impeller can be an effective device to control the axial thrust of the pump. The vanes disturb circumferential flow of the cavity and it can modify the axial force acting on the impeller. In this paper, three types of vanes are installed in the high-speed centrifugal pump for liquid rocket engines and the thrust of the pump is measured with an additional thrust measurement unit. According to the results, shapes of cavity vanes have effects on the axial thrust of the pump. As the height of vanes increases, the outlet pressure of the rear floating ring seal decreases which results in a decrease of the thrust. On the other hand, head of the pump is almost same regardless of cavity vanes. Also, the pressure drop of the bypass pipeline increases when vanes are removed.

• Journal of the Korean Society of Propulsion Engineers
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• v.12 no.1
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• pp.1-6
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• 2008

Performance test of the 30-ton class liquid rocket engine turbopump turbine has been conducted using high pressure cold air. Overall performance of the two kinds of turbine rotors - rotor with knife-edged L.E blades and with rounded L.E blades - has been measured for various rotational speed and turbine pressure ratio. The effect of rotational speed and turbine pressure ratio on the turbine axial force behavior also has been measured in parallel. Test results have revealed that the efficiency of knife edged L.E. turbine is a little bit higher than that of rounded L.E. turbine. The axial force of the turbine varied linearly with respect to rotational speed and its magnitude largely depended on turbine pressure ratio.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.569-572
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• 2010

In order to study the performance characteristics of the thrust vector nozzle, the test facility and instrumentation system were designed. In this system, axial thrust, moment, exhaust gas velocity and pressure will be measured by using the scale down experimental model devices. The test facility are composed of high pressure air storage system, flow measuring and control system, test nozzle and thrust measurement system.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.47 no.3
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• pp.19-27
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• 2010

KSLV(Korea Space Launch Vehicle)-I is designed as a launch vehicle to enter a 100 kg-class satellite to the LEO(Low-Earth Orbit). Attitude angles of the upper-stage, including roll, pitch and yaw are controlled by cold gas thruster system using nitrogen gas. The thruster for the KSLV-I is the main pneumatic valve in the RCS(Reaction Control System). In this paper, the design, function tests, and environment tests of the thruster for KSLV-I are described. The developed thrusters are experimentally evaluated and successfully passed the required qualification and acceptance tests.