• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2005.11a
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• pp.29-33
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• 2005

In the fuel of the solid fuel ramjet there are metal particles in order to improve the Isp like as solid rocket propellants. Because of the short combustion residence time these metallized fuels have low combustion efficiencies. Therefore it is necessary to increase the combustion efficiency and the inlet air temperature does an important role to this. The effect of the inlet air temperature to the performance is investigated through the semi-empirical method by adopting the experimental combustion efficiency. There are two factors to affect the inlet temperature, free stream temperature and the flight Mach number.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.04a
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• pp.272-275
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• 2007

The combustion efficiency of the solid fuel ramjet is affected by the inlet air temperature. And this inlet air temperature is dependent on the flight Mach number and the environment air temperature. If the flight altitude is changeable, the inlet air temperature and also the air density vary. The performance efficiency is investigated with this variables related to the combustion efficiency.

• Journal of the Korean Society of Propulsion Engineers
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• v.8 no.2
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• pp.95-101
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• 2004

An experimental investigation was conducted to investigate the effects of the equivalence ratio and air mass flux on the combustion efficiency in a solid fuel ramjet used fuel grains which were highly loaded with boron carbide. Combustion efficiency increased with increasing equivalence ratio (grain length), and decreasing air mass flux. Higher inlet air temperature produced higher combustion efficiencies, apparently the result of enhanced combustion of the larger boron particles those burn in a diffusion controlled regime. Short grains which considered primarily of the recirculation region produced larger particles and lower combustion efficiencies. The result of the normalized combustion efficiency increased with inlet air temperatures coincident with the result of the Brayton cycle thermal and the total efficiency relating to the heat input.

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

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1993.10a
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• pp.55-61
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• 1993

An experimental investigation was conducted in order to determine the flammability limit of the solid fuel ramjet using the backward facing step flow combustion of the plexiglass grain. In order to get the different step height ratio, the grain was drilled straight forward or stepwise. The Phoenics computer code was adopted in order to compare. the flow patterns of the some sample tests using a non-reacting cold turbulent flow model. The stepwise grain give some loading advantage; specially thin and long shape grain design.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.508-512
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• 2017

In this study, we carried out the study on the combustion characteristics of HTPB/AP propellants with Al and Zr as fuel metal in order to develop the solid propellant with high burning rate. The major combustion characteristics of propellant were investigated as measuring of the burning rate and pressure exponent, and the HTPB/AP solid propellants were prepared with introducing Butacene as burning rate catalyst for the enhancement of burning rate. The propellant with Al and Zr was demonstrated the improvement of propellant performance and combustion characteristic.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.6
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• pp.9-16
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• 2010

The SFRJ(Solid Fuel Ram-Jet) propulsion is attractive for projectiles because of the combination of high propulsive performance and low system complexity more than conventional projectiles. The Objective of this research was to characterize the inlet aerodynamic characteristics (center-body & pitot type) in SFRJ. Diffuser static pressure & combustion chamber pressure was tested and the AoA was changed $0^{\circ}$ and $4^{\circ}$ at Mach number of 3.0 for performance estimate. The performance study of inlet was carried out with the Schlieren system and Supersonic cold-flow system. Under mach 3.0, the center-body showed twice higher total pressure recovering ratio than the pitot type. A Computational fluid dynamic solution is applied internal flow of inlet and the solutions are compared with experimental results.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.05a
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• pp.89-92
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• 2008

In generally, the regression rate equation was only expressed by function of oxidizer massflux in hybrid propulsion system. This can not represent the local value of regression rate along with oxidizer flow direction. In this study, experimental studies were performed with several pieces of solid fuel. As results, the local regression rate decreases rapidly with axial location near entrance, and increases with axial distance from the leading edge. The empirical formula for local regression rate with function of oxidizer massflux and length was derived.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.6
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• pp.87-94
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• 2019

This paper contains the process of investigating the cause of fuel filter contamination of P&WC's PT6A-67A engine. An outline of the fuel filter contamination and configuration of the fuel supply line are specified. The analytical methods were classified into fuel component analysis and solid sediment analysis(EDX, TGA, optical microscope). In summary, the sulfur was detected from fuel tank sealant as a major contamination component. As a follow-up, P&WC and the Agency for Defense Development will conduct engine fuel filter cycle checks and fuel tank cleaning for engine operation.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.05a
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• pp.77-81
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• 2008

The local regression rate behavior of solid fuel in swirl injection hybrid rocket were studied. In generally, axial injection regression rate was tending to be decrease with axial distance, beyond which increased with increasing axial distance from the leading edge. On the other hand, swirl injection regression rate was high at the leading edge of the fuel and comparatively uniform regression rate at the downstream. Overall regression rate of swirl injection was increased about 54% for the overall regression rate of axial injection. Through this study, it was found that using swirl injector was useful in applying to the small sounding rocket.