• Journal of the Korean Society of Propulsion Engineers
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• v.6 no.1
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• pp.21-29
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• 2002

Hybrid propulsion systems provide many advantages in terms of stable operation and safety. However, classical hybrid rocket motors have lower fuel regression rate and combustion efficiency compared to solid propellant rocket motor. The recent research efforts are focused on the improvement of volume limitation and regression rate in the hybrid rocket engine. The present study has numerically investigated the combustion processes in the hybrid rocket engine. The turbulent combustion is represented by the eddy breakup model and Hiroyasu and Nagle and Strickland-Constable model are used for soot formation and soot oxidation. Radiative heat transfer is modeled by finite volume method. To reduce the uncertainties for convective heat transfer near solid fuel surface having strong blowing effect, the Low Reynolds number $\kappa-\varepsilon$ turbulent model is employed. Based on numerical results, the detailed discussion has been made for the turbulent combustion processes in the vortex hybrid rocket engine.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.10a
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• pp.122-125
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• 2003

For Lab-scale Hybrid Rocket's Ignition, It is needs of heat source to vaporize solid fuel. We used Nichrome wire which has a electric resistance for ignition. But Ignition system by using Nichrome wire is not only the disposable system, but also the system which has an affect on the Hybrid rocket's structures(nozzle throat diameter). The new Ignition system composed of Butane+propane gas' supply devices and spark plug. RPL(Rocket Propulsion Lab.) perform the hybrid rocket experiments over 50 times by using new ignition system. The fact that is possible to throttle the Thrust in hybrid rocket is confirmed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.353-357
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• 2017

The research trends and major technologies of the divert attitude control system(DACS), which is the core of the anti-missile system, are described. The operating concept and characteristics according to the fuel used are summarized. The characteristics of typical weapon system applying solid(SM3 Block IB/IIA) and liquid(THAAD) fuels were discussed. In the future, it will be necessary to study various types of DACS in the strategic concept of the defense weapon system.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.2
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• pp.38-51
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• 2018

This study was carried out to improve the performance characteristics of nozzleless boosters that are used in ramjet boosters. A propellant using Zr as the metal fuel was developed, which provided a higher density than the propellant using Al as the metal fuel. The developed propellant was cast using the nozzleless booster and a ground test was carried out by varying the length-to-diameter ratio (L/D ratio) of the propellant. From a comparison between the performance characteristics of propellants using Zr and Al, it was proved that the performance of the propellant using Zr is higher than that of propellant using Al, except for the specific impulse, under all tested conditions. As the length-to-diameter ratio was increased, the specific impulse of the propellant using Zr was decreased by 88% compared with that of the propellant with Al. However, because of the density difference between the propellants, the impulse density of the propellant with Zr was higher than that of the propellant with Al under all tested conditions.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.4
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• pp.448-454
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• 2010

The strengthened regulations for atmospheric emissions from ships have caused a necessity of new, alternative power system in ships for the low pollutant emissions and the high energy efficiency. Recently, new kinds of propulsion power system such as fuel cell system, which use hydrogen as an energy source, have been sincerely considered. The purpose of this work is to predict the performance of methanol fueled SOFC system and to analyze the influence of operating temperature, current density, S/C, and $H_2$ utilization ratio.

• Journal of the Korean Society of Propulsion Engineers
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• v.9 no.4
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• pp.31-38
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• 2005

In this paper, the combustion characteristics of a hybrid propulsion system were studied with various L/D(length vs diameter) ratio of the single po.1 type solid fuel. Experiments were performed for 2 cases with the fixed grain port diameter and fuel length respectively. For the first case, results show that there are no large variations for regression rates as the L/D ratio changes. And as the L/D ratio increases, the O/F ratio decreases and thrust, characteristic velocity tends to increase. For the second case, there is no large change for O/F ratio, thrust and characteristic velocity as L/D ratio changes. On the other hand, as the L/D ratio decreases, only the regression rate tends to increase. Experimentally, exponent n in $\dot{r}=a{G_0}^n$ was found about 0.5 and then the O/F ratio was shown nearly constant. In the experiment, PE and gas oxygen were used as a fuel and an oxidizer.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.5
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• pp.27-36
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• 2013

Linear stability analysis for combustion instability within a cylindrical port of solid rocket motor has been conducted. The analysis of acoustic energy has been performed by a commercial COMSOL code to obtain the mode function associated to each acoustic mode prior to the calculation of stability alpha. An instability diagnosis based on the linear stability analysis of Culick is performed where special interests have been focused on 5 stability factors(alpha) such as pressure coupling, nozzle damping, particle damping and additionally, flow turning effect and viscous damping to take into account the flow and viscosity effect near the fuel surface. The instability decay characteristics depending on the particle size is also analyzed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.11a
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• pp.207-210
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• 2008

We developed an integrated design system for a solid rocket motors. We can do a conceptual design of a solid rocket motor easily and quickly with this system. It consists of four modules, or, size design, structure design, grain design and performance analysis module. Size design module determines the lengths and diameters of some major parts, which results in fixing the whole size of a motor. Structure design module has many master models, which enables a designer can do a conceptual design of almost parts of motor structures. Grain design module can design a solid fuel according to the result of structure design. Finally performance analysis module verifies the proposed design with the output from grain design module.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.1
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• pp.18-24
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• 2015

An experimental investigation was conducted to figure out the effects of the inlet air temperature on the combustion efficiency using the fuel grains which were highly loaded with boron carbide. The results showed that the normalized combustion efficiency increased with the inlet air temperature, apparently the result of enhanced combustion of the boron particles. Even though the combustion efficiency is increased, the overall efficiency through the semi-empirical method, is decreased with the increasing inlet air temperature. Brayton cycle analysis has been performed using the heat input parameter and combustor Mach number, those two parameters are important role for the performance and similar trends are shown at the experimental results.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.206-209
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• 2010

The visualization device for hybrid rocket is fabricated to investigate the combustion phenomena. Visualization device were composed with ignition system, oxidizer supply system, control system and data acquisition system, combustion visualization system. GOX as oxidizer and HDPE, Paraffin-LDPE Blending, Paraffin sd were used. As results, combustion phenomena and fuel droplet entrainment were observed.