• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.05a
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• pp.233-238
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• 2006

Hybrid rocket had many advantage with compared to solid and liquid rockets. In this study, swirl flow hybrid motor was designed and manufactured. And the methods of regression rate improvement were considered. Thrust was calculated with pressure of the combustion chamber and the regression rate was measured by using ultrasonic sensor technique in entire firing conditions. In this study, PMMA fuel and HTPB solid fuel were used in firing test.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2005.11a
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• pp.311-317
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• 2005

Hybrid rocket had many advantage with compared to solid and liquid rockets. In this study, swirl flow hybrid motor was designed and manufactured. And the methods of regression rate improvement were considered. Thrust was calculated with pressure of the combustion chamber and the regression rate was measured in low flow rate of oxidizer. Several problems and solutions of operating hybrid rocket was presented.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.429-431
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• 2011

The characteristics of hydro-reactive metal fuel(HRF) propellant on motor performances such as specific impulse and chamber temperature were analyzed by thermodynamic calculation methods. The thermal analysis and burning rate experiments of HRF propellants were also carried out for studying effects of metal fuels on combustion properties.

• Journal of the Korean Magnetics Society
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• v.7 no.6
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• pp.321-326
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• 1997

We analyzed an important part of control valve, magnet unit, which is used to control the fluid. Magnetic circuit which is composed of magnet and yoke is analyzed using finite element method. Then, flux density and coil force were calculated and compared with those of measured. According to the simulation results, the gap field, force constant, and permeance coefficient were 3~5 kG, 27.5 N/A, 22.1, respectively, which corresponded reasonably well with the measured values. We also obtained reluctance factor of 1.1 and fringing factor of 1.4 by simulation.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.10a
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• pp.126-130
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• 2003

Hybrid rocket had many advantage with compared to solid and liquid rockets. In this study, lab-scale hybrid motor was designed and manufactured. And the methods of regression rate improvement were considered. Thrust was calculated with pressure of the combustion chamber and the regression rate was measured in low flow rate of oxidizer. Several problems and solutions of operating hybrid rocket was presented.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2001.04a
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• pp.35-38
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• 2001

The aerothermodynamic characteristics of SCRamjet engine for the airbreathing populsion system of the next generation flight vehicle are described. As the flow is passing by, combustion caused the total pressure loss and the Mach number decrease, but nozzle exit velocity is large enough to produce net thrust. To simulate supersonic combustion test, preliminary design of ground-based blowdown type supersonic combustion tunnel is attained. Minimum allowable operating pressure and mass flow rate are calculated for the design Mach number of 2.5 at the test section of a supersonic combustion tunnel.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.05a
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• pp.262-265
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• 2003

This Study is focused on the instrumenting Hybrid Rocket Motor of ACPL at Konkuk University and researching combustion instability by measuring regression rate versus oxidizer mass flux. In the result of experiment, test fire was moderate and we could acquire data of pressure, thrust, and temperature of combustion chamber. In the future, studying unsteady change of regression rate and pressure characteristic analysis of combustion chamber through hundreds of experiments should be performed. furthermore, researching characteristic velocity by taking a measurement of combustion temperature will be inevitable.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.32-34
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• 1997

For a given brushless DC linear motor, we suggest the numerical prediction methods to analyze it's thrust characteristics. First, we calculate the magnetic flux density by the finite element method, and we then compute the maximum thrust with three computational methods - a Lorentz equation, a Maxwell stress method and a virtual work method. To confirm the accuracy of the computational methods, we measure the thrust of the linear motor made by our laboratory with a force-torque sensor. Also, we calculate the thrust by the measured back electromotive force. To choose the appropriate method for a specified application, we compare the maximum thrusts of the computational method and the calculation by the back electromotive force with the measured one. We conclude that the Maxwell stress method is turned out the best because it has the most accurate results among three computational methods and it is more convenient than the calculation method by the back electromotive force.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.912-913
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• 2015

자동차의 오토 기어를 능동적으로 제어하기 위해 전자기력을 이용한 원통형 선형 보이스 코일 전동기를 설계 하였다. 설계 시 유한 요소 해석 프로그램을 이용해 각 부품의 자기 포화 밀도 및 코일에 인가되는 자속을 계산하여 성능을 예측하였다. 기본모델에 대해 중량을 최소화한 모델을 제작하여 실험한 결과 추력은 기본모델과 비슷한 상태에서 중량이 약 40% 감소하였다.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.96-98
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• 2001

In this paper, the equivalent magnetic circuit and FEM are used to calculate force density of linear BLDC motor. The equivalent magnetic circuit is hard to exact compose for analysis model and it is just applied to linear system. To flexible design and reducing the calculated and analyzed time, magnetic circuit has to be used for designing the linear BLDC motor and deducing equation of force density. Force density as parameter of permanent magnet and coil-side width that are important to determined force density can be estimated using equation of force density. FEM is used to prove reliability of equation of force density and to consider the nonlinear system. Equivalent magnetic circuit and result of FEM are similar, but it is little different by friction loss at the experiment.