• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.11 no.9
• /
• pp.398-405
• /
• 2001

The maximum and mean indicated pressure of two stroke low speed diesel engine has been continuously increased with a view of increasing engine power and also reducing fuel consumption. As a result, axial excitation has been increased comparing to that of the previous one. So the axial vibration damper in standard one is applied to all two stroke low speed diesel engine at the free end of crankshaft. Though many studies were carried out for marine use, few has been made for diesel power plant because there was little demand for power plant. Nowadays, diesel engine is much to be used for many benefits. In this paper, the optimum design of axial vibration on the 65 kW diesel power plant with tow 9K80MC-S engines of 9 cylinders was carried out. And the axial-torsional coupled vibration of this shafting system is identified by theoretical analysis and vibration measurement.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.5 no.4
• /
• pp.67-74
• /
• 2001

Based on the national space development project, the necessity of developing liquid propellant rocket engine is revealed to secure the basic technology for the development of individual artificial-satellite launcher. Consequently, KARI (Korea Aerospace Research Institute) is developing a liquid propellant rocket engine for the KSR-III. Currently, a prototype engine using kerosene/LOx which produces 13-ton thrust is designed, fabricated and tested. In this paper, test procedure and technique for liquid propellant rocket engine are introduced with the analysis of static and dynamic test data.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.44 no.2
• /
• pp.116-122
• /
• 2016

The performance characteristics of a TBCC engine considering the transition mode from a turbojet to a ramjet engine has been investigated. The performance of each engine was proposed and a transition mode of the TBCC engine has been evaluated by adjusting the operating rate of the ramjet engine and turbojet engine performance changes continuously. Based on the transition model, it was confirmed that the performance is continuously changed at various flight Mach numbers and altitudes. The performance characteristics including thrust and specific impulse considering various flight conditions and transition mode were analyzed, which testifies characteristics of the engine itself, as well as transition of the combined cycle.

• Aerospace Engineering and Technology
• /
• v.9 no.2
• /
• pp.98-104
• /
• 2010

The moisture in the atmosphere exerts a lot of influence upon Gas turbine engine performances. There is a noticeable influence of wet air at the summer sea level, high flight mach number and low engine rpm increasingly. An altitude Engine Test Facility is used to accomplish the engine performance tests at dry air condition and wet air condition, through which engine performance results is revealed. Also, Gas turbine Simulation Program is used to predict the variation of engine performance due to inlet humidity. In the result, net thrust and specific fuel consumption measured -2.826% and 1.325%, respectively at wet air condition compared to dry air condition.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2010.11a
• /
• pp.335-338
• /
• 2010

The moisture in the atmosphere exerts a lot of influence upon Gas turbine engine performances. There is a noticeable influence of wet air at the summer sea level, high flight mach number and low engine rpm increasingly. An altitude Engine Test Facility is used to accomplish the engine performance tests at dry air condition and wet air condition, through which engine performance results is revealed. In the result, net thrust and specific fuel consumption measured -2.826% and 1.325%, respectively at wet air condition compared to dry air condition.

• Journal of Astronomy and Space Sciences
• /
• v.28 no.3
• /
• pp.203-216
• /
• 2011

To prepare for a future Korean lunar orbiter mission, semi-optimal lunar capture orbits using finite thrust are designed and analyzed. Finite burn delta-V losses during lunar capture sequence are also analyzed by comparing those with values derived with impulsive thrusts in previous research. To design a hypothetical lunar capture sequence, two different intermediate capture orbits having orbital periods of about 12 hours and 3.5 hours are assumed, and final mission operation orbit around the Moon is assumed to be 100 km altitude with 90 degree of inclination. For the performance of the on-board thruster, three different performances (150 N with $I_{sp}$ of 200 seconds, 300 N with $I_{sp}$ of 250 seconds, 450 N with $I_{sp}$ of 300 seconds) are assumed, to provide a broad range of estimates of delta-V losses. As expected, it is found that the finite burn-arc sweeps almost symmetric orbital portions with respect to the perilune vector to minimize the delta-Vs required to achieve the final orbit. In addition, a difference of up to about 2% delta-V can occur during the lunar capture sequences with the use of assumed engine configurations, compared to scenarios with impulsive thrust. However, these delta-V losses will differ for every assumed lunar explorer's on-board thrust capability. Therefore, at the early stage of mission planning, careful consideration must be made while estimating mission budgets, particularly if the preliminary mission studies were assumed using impulsive thrust. The results provided in this paper are expected to lead to further progress in the design field of Korea's lunar orbiter mission, particularly the lunar capture sequences using finite thrust.

• Journal of Ocean Engineering and Technology
• /
• v.33 no.1
• /
• pp.1-9
• /
• 2019

This paper considers a numerical assessment of the self-propulsion performance of a damaged ferry carrying cars in irregular waves. Computational fluid dynamics(CFD) simulations were performed to see whether the ferry complied with the Safe Return to Port (SRtP) regulations of Lloyd's register, which require that damaged passenger ships should be able to return to port with a speed of 6 knots (3.09 m/s) in Beaufort 8 sea conditions. Two situations were considered for the damaged conditions, i.e., 1) the portside propeller was blocked but the engine room was not flooded and 2) the portside propeller was blocked and one engine room was flooded. The self-propulsion results for the car ferry in intact condition and in the damaged conditions were assessed as follows. First, we validated that the portside propeller was blocked in calm water based on the available experimental results provided by KRISO. The active thrust of starboard propeller with the portside propeller blocked was calculated in Beaufort 8 sea conditions, and the results were compared with the experimental results provided by MARIN, and there was reasonable agreement. The thrust provided by the propeller and the brake horsepower (BHP) with one engine room flooded were compared with the values when the engine room was not flooded. The numerical results were compared with the maximum thrust of the propeller and the maximum brake horse power of the engine to determine whether the damaged car ferry could attain a speed of 6 knots(3.09 m/s).

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2011.11a
• /
• pp.842-849
• /
• 2011

Open Rotor Engine is one of the several new technologies offering potential solution for the next generation aircraft. The coupling of ultra high bypass ratio and aerodynamically advanced fan blade design allow the open rotor engine to achieve and advantage in fuel consumption. The open rotor engine does have more thrust lapse than the general high bypass turbofan. The open rotor engine performance model was analyzed using a reference data based on the GE36 which was designed and tested data at which time a F404 turbojet was used as the core. The performance model of open rotor engine was verified by referred test data and was evaluated to be properly constructed, through the comparison of recent Next generation turboprop engine performance.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2008.05a
• /
• pp.349-352
• /
• 2008

This work is to observe combustion characteristics depending on variation of the solid propellent grain configuration. The LRE (Liquid Rocket Engine) enables adjusting the thrust by controling the required fuel mass glow, but the SRM(Solid Rocket Motor)is not easy to adjust th thrust due to the difficulty of th fuel flow control by its combustion behavior even its configuration is simple. This difficulty can be partly solved by changing th size or the configuration of the propellant grain. In this study a proper grain configuration of a small solid rocket is selected through both the theoretical design and the experimental tests.

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