• Journal of the Korean Society of Propulsion Engineers
• /
• v.24 no.6
• /
• pp.126-142
• /
• 2020

This study aims to provide basic design data for a pintle injector and its combustion device through case study on the research and development of combustion devices to which a liquid-liquid pintle injector was applied. From data analysis, it was possible to provide the initial dimension of the combustion chamber and pintle injector based on the engine thrust, and the geometric characteristics of the high-efficiency injector. In addition, the pintle tip heat damage prevention mechanism and materials, face-shutoff pintle injector implementation method, and central propellant selection criteria were summarized. Theses results will be used as basic data for the design criteria of an initial pintle injector combustion device.

• Aerospace Engineering and Technology
• /
• v.9 no.2
• /
• pp.168-175
• /
• 2010

During feeding oxidizer to the engine, vortices are occurred at lower dome of oxidizer tank inside by various working environments and external forces for liquid propellant feeding system of space launch vehicle. To eliminate the vortices or swirls Anti-Vortex Devices(AVD) shall be installed at inside lower oxidizer tank. Using the numerical analysis, we have confirmed the performance of AVD and analyzed the mass flow rate by feeding time and magnitudes of swirls on the free surface of oxidizer or exit surface according to the AVD number and length. Then we could derive the optimal design of the AVD number and length.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.34 no.10
• /
• pp.56-60
• /
• 2006

It is essential to predict thermodynamic properties of combustion gas with respect to a propellant mixture ratio for the development of a gas generator for a liquid rocket engine. The present study shows the temperature measurement of exit combustion gas as a function of a mixture ratio through the series of combustion tests of a fuel-rich gas generator with liquid oxygen and Jet A-1. The measurements of dynamic and static pressures, and combustion gas temperatures allowed the estimation of thermodynamic properties like a specific heat ratio, a gas constant, and a constant pressure specific heat of the combustion gas. The comparison of the experimental results with predictions made by interpolation parameters obtained from the modification of the chemical equilibrium code indicates that the interpolation method calibrated using the temperature measurements can be utilized as an effective tool for the initial design of a fuel-rich gas generator.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.18 no.6
• /
• pp.53-62
• /
• 2010

An airbag is composed of housing assembly, door assembly, cushion assembly, and an inflator. The inflator is the essential part that generates gas for airbag. When an airbag is activated, it effectively absorbs the crash energy of the passenger by inflating a cushion. In this study, tank tests were performed with newly synthesized propellants with various compositions, and the results are compared with the numerical results. In the simulation of inflator, a zonal model has been adopted which consisted of four zones of flow regions: combustion chamber, filter, gas plenum, and discharge tank. Each zone was described by the conservation equations with specified constitutive relations for gas. The pressure and temperature of each zone of the inflator were calculated and analyzed and the results were compared with the tank test data. In the zone of discharge tank the pressure quickly rose, the pattern of pressure curve was very similar to the pressure curve of real test. And in zone 1 & 2 & 3 the mass of products was increased and decreased with time. In zone 4, the mass of products was increased with time like real inflator. From the similarity of pressure curve in zone 4 and closed bomb calculation the modeled results are well correlated with the experimental values.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2011.11a
• /
• pp.336-339
• /
• 2011

Hot-fire test facility is one of the most important infrastructure for thruster development and evaluation. During the past three years, Korea Aerospace Research Institute (KARI) and Hanwha Corporation have successfully performed the construction of hot-fire test facility for medium-scale monopellant thruster to the maximum 200N thrust level. In general, thruster hot-firing test should be performed in vacuum conditions to simulate space environment. The hot-fire test facility is divided into three subsystems, vacuum system, propellant supply system and data measurement & control system. The goal of this facility is to extend the capability from small thruster for satellite mission to medium-scale thruster for launch vehicle and lunar mission. In this paper, the progress and overview for thruster hot-fire test facility was introduced and test results were also presented.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.14 no.5
• /
• pp.8-14
• /
• 2010

For the development of a liquid rocket engine, hot-firing tests of a regeneratively cooled thrust chamber were performed at chamber pressures of approximately 30 and 60 bars. In the paper, pressure fluctuation data, which were obtained from the dynamic pressure transducers installed in propellant manifolds and combustion chamber, were analyzed. Compared to the data at chamber pressure of 60 bar, the results at chamber pressure of 30 bar showed low-frequency oscillations around 150 Hz in the combustion chamber. The low-frequency waves in the combustion chamber were coupled with those in the manifolds. However, the RMS values of the chamber pressure fluctuations at chamber pressure of 30 bar were only 0.8% of the chamber pressures. Thus, it can be inferred that the thrust chamber operates in the stability boundary even at low chamber pressure.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.47 no.11
• /
• pp.803-811
• /
• 2019

Water rocket is a non-chemical rocket mechanically powered by pressurized gas and liquid (water) propellants. Since water rockets share many engineering commonalities with liquid propellant rockets for space launch vehicles, it is as a education tool for rocket engineering. Present paper investigated the availability of water rocket as an engineering education model by surveying the history of water rocket and making examples from K-12 education, commercial products and club activities. Finally, a way of improvement is suggested for water rocket competitions make changes in the perception on water rockets by examining the limitations of present competitions.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.26 no.5
• /
• pp.35-43
• /
• 2022

Precise modeling and analysis of closed bomb test(CBT) combustion using solid propellants was performed. The fluid structure interaction(FSI) method was implemented to analyze the gas and solid phases at the same time. The Eulerian analysis method was applied for the gas phase and grain combustion, and the Lagrangian analysis method was implemented for the grain movement. The interaction between the solid phase grains and the combustion gas was fully coupled through the source term. The volume of fluid(VOF) method was used to simulate the burning distance of the grain and the movement of the combustion surface. The force acting on the grain was comprised of the pressure and gravity acting on the grain burning surface, and the grain burning rate and grain movement speed were considered in the velocity term of the VOF. The combustion analysis was performed for both one and three grains, and fairly compared with the experiments. The acoustic field during grain combustion due to pressure fluctuations was also analyzed.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.26 no.6
• /
• pp.34-42
• /
• 2022

A correlation between propellant supply condition and chamber pressure in GCH₄-LOx small rocket engine was explored and hot-firing tests were conducted to analyze the engine performance characteristics according to the equivalence ratio variation at a constant chamber pressure. Correlation studies have shown that chamber pressure is linearly proportional to oxidizer supply pressure. As a result of the test, the thrust, specific impulse and characteristic velocity that are the main performance parameters of a rocket engine, were found to be enhanced as the equivalence ratio starting from a fuel-lean condition approached the stoichiometric ratio, but the efficiencies of characteristic velocity and specific impulse were on the contrary, in their dependency on the equivalence ratio.

• Clean Technology
• /
• v.25 no.3
• /
• pp.256-262
• /
• 2019

Hydroxylammonium nitrate (HAN)-based liquid propellants are attracting attention as environmentally friendly propellants because they are not carcinogens and the combustion gases have little toxicity. The catalyst used to decompose the HAN-based liquid propellant in a thruster must have both low temperature activity and high heat resistance. The objective of this study is to prepare an Ru/alumina/metal foam catalyst by supporting alumina slurry on the surface of NiCrAl metal foam using a washing coating method and then to support a ruthenium precursor thereon. The decomposition activity of a HAN aqueous solution of the Ru/alumina/metal foam catalyst was evaluated. The effect of the number of repetitive coatings of alumina slurry on the physical properties of the alumina/metal foam was analyzed. As the number of alumina wash coatings increased, mesopores with a diameter of about 7 nm were well-developed, thereby increasing the surface area and pore volume. It was optimal to repeat the wash coating alumina on the metal foam 12 times to maximize the surface area and pore volume of the alumina/metal foam. Mesopores were also well developed on the surface of the Ru/alumina/metal foam catalyst. It was found that the metal form itself without the active metal and alumina can promote the decomposition reaction of the HAN aqueous solution. In the case of the Ru/alumina/metal foam-550 catalyst, the decomposition onset temperature was significantly lowered compared with that of the thermal decomposition reaction, and ${\Delta}P$ could be greatly increased in the decomposition of the HAN aqueous solution. However, when the catalyst was calcined at $1,200^{\circ}C$, the catalytic activity was lowered inevitably because the surface area and pore volume of the catalyst were drastically reduced and Ru was sintered. Further research is needed to improve the heat resistance of Ru/alumina/metal foam catalysts.