• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2011.11a
• /
• pp.645-648
• /
• 2011

Hydrazine which has been used as monopropellant shows high performance, but because of its high toxicity research for new green propellant that could replace hydrazine is going on. Ionic liquid propellant that is one of the green propellant has lower toxicity, higher specific impulse, and higher density than hydrazine. To design the thruster which use Hydroxylamine Nitrate (HAN), one of ionic liquid propellant, as a propellant, a quantity of catalyst for full decomposition of a propellant is needed. In this study, reference point for HAN thruster design could be suggested through a design of a small scale thruster which used HAN propellant, and propellant decomposition capability evaluation with characteristic velocity efficiency.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2007.04a
• /
• pp.168-171
• /
• 2007

A technical review of current slurry and gelled propellants is presented. In advanced countries, it is confirmed that these propellants have high specific impulse, density, excellent handling, safety characteristics and thrust controllability through research since 1950s. Substantial researches have been pursued to characterize the rheological properties, spray/combustion phenomena and propulsion system design for the gel propellant characteristics. Slurry and gelled propellants are developing actively to applicate both military and space propulsion fields such as tactical missile, air-breathing ramjet, pulse detonation engine, and combined cycle engine of future propulsion mode.

• Bulletin of the Korean Chemical Society
• /
• v.35 no.4
• /
• pp.989-993
• /
• 2014

The molecular structures of 2,6-diaza-1,3,5,7-tetraoxaspiro[3,3]heptane (1) and its dinitro derivative, 2,6-dinitro-2,6-diaza-1,3,5,7-tetraoxaspiro[3,3]heptane (2), were fully optimized without symmetry constraints at $HF/6-31G^*$ level of theory. A bisected conformation with respect to the ring is preferred with a $C_2$ symmetric structure. The density of each molecule in the crystalline state was estimated to 1.12 and 2.36 $g/cm^3$ using PM3/VSTO-3G calculations from the molecular volume. The heat of formation was calculated for two compounds at the CBS-4M level of theory. The detonation parameters were computed using the EXPLO5 software: D = 6282 m/s, $P_{C-J}$ = 127 kbar for compound 1, D = 7871 m/s, $P_{C-J}$ = 307 kbar for compound 2, and D = 6975 m/s, $P_{C-J}$ = 170 kbar for 60% compound 2 with 40% TNT. Specific impulse of compound 1 in aluminized formulation when used as monopropellants was very similar to that of the conventional ammonium perchlorate in the same formulation of aluminum.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.4 no.3
• /
• pp.74-82
• /
• 2000

The concept and characteristics of the propulsion systems for the next generation flight vehicles are described in this paper, where Hey are grouped into air breathing engine, rocket engine and combined cycle engine according to the feeding system of oxidizer. Air breathing engine has its good reusability and superior performance at low altitude, but its usage is limited at high altitude due to the decreased air density. Rocket engine can be used over the wide range of altitude, but it has disadvantages in low specific impulse and high cost. The several types of combined cycle engine, which are being developed by the leading countries in the aerospace, are highlighted as a remarkable candidate for the next generation propulsion system.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2017.05a
• /
• pp.406-408
• /
• 2017

Ammonium dinitramide (ADN) Low toxicity monopropellant based 1N class thruster and test equipment were developed. Compared with the hydrazine which used in existing satellite thruster, ADN is easy to handle and has excellent physical characteristics such as density and specific impulse. Due to these characteristics, ADN is attracting attention as an eco-friendly propellant. In this paper, 1N class thruster and thrust measurement system was designed for performance testing of ADN monopropellant. The composition of the propellant for the design and experiment was set at 11.2: 25.4: 63.4 for each of Methanol: $H_2O$: ADN.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.37 no.7
• /
• pp.717-728
• /
• 2009

In the field of rocket propulsion system hydrogen peroxide has been used as mono-propellant and as the oxidizer of bi-propellants. At the beginning, hydrogen peroxide was used as mono-propellant for thrusters, but later it had been replaced by hydrazine, which has better specific impulse and storability. On the other hand, to drive turbo-pumps, hydrogen peroxide is still being utilized. As the oxidizer of bi-propellants it was used until 1970's and from 1990's hydrogen peroxide once again got back to developer's interest, because one of the recent development purposes of rocket propulsion system is low-cost and ecologically-clean. Until now the storability of hydrogen peroxide has been remarkably improved. The combination of Kerosene/$H_2O_2$ also shows similar accelerating performance to Kerosene/$LO_x$ combination because of higher propellant density and higher O/F ratio, even though the propulsion performance is not as good as the combination of Kerosene/$LO_x$. Moreover, its combustion products are much cleaner than Kerosene/$LO_x$ combination.

• Journal of the Korean institute of surface engineering
• /
• v.47 no.3
• /
• pp.109-115
• /
• 2014

High power impulse magnetron sputtering (HIPIMS), also known as the technology is called peak power density in a short period, you can get high, so high ionization sputtering rate can make. Higher ionization of sputtered species to a variety of coating materials conventional in the field of improving the characteristics and self-assisted ion thin film deposition process, which contributes to a superior being. HIPIMS at the same power, but the deposition speed is slow in comparison with DC disadvantages. Since recently as a replacement for HIPIMS modulated pulse power (MPP) has been developed. This ionization rate of the sputtered species can increase the deposition rate is lowered and at the same time to overcome the problems to be reported. The differences between the MPP and the HIPIMS is a simple single pulse with a HIPIMS whereas, MPP is 3 ms in pulse length is adjustable, with the full set of multi-pulses within the pulse period and the pulse is applied can be micro advantages. In this experiment, $In_2O_3$ : $SnO_2$ composition ratio of 9 : 1 wt% target was used, Ar : $O_2$ flow rate ratio is 4.8 to 13.0% of the rate of deposition was carried out at room temperature. Ar 40 sccm and the flow rate of $O_2$ and then fixed 2 ~ 6 sccm was compared against that. The thickness of the thin film deposition is fixed at 60 nm, when the partial pressure of oxygen at 9.1%, the specific resistance value of $4.565{\times}10^{-4}{\Omega}cm$, transmittance 86.6%, mobility $32.29cm^2/Vs$ to obtain the value.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2011.04a
• /
• pp.85-88
• /
• 2011

In the trend of world wide environment preservation, researchers tried to find new environment friendly propellant instead of highly toxic propellant, Hydrazine. Among the candidates, ionic liquid propellants have lower toxicity, higher density, and higher specific impulse than Hydrazine. These ionic liquid propellants have high combustion chamber temperature, so catalyst supports such as gamma alumina cannot withstand in that temperature. Therefore, a catalyst that showed stable characteristic in high temperature is needed. Barium dopped alumina can be changed to Hexaaluminate in high temperature, and its characteristic in high temperature is superior than gamma alumina. Barium dopped Alumina is wet impregnated with Platinum and heated up to $1300^{\circ}C$ and $1400^{\circ}C$ for 2 hours. Those catalysts were examined by XRD, SEM, EDS, BET, and Drop test.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.26 no.6
• /
• pp.86-100
• /
• 2022

In this paper, the concept and characteristics of the nuclear propulsion system were introduced and the state of the art for the nuclear-powered space propulsion in abroad were summarized. Since uranium used in nuclear propulsion has a very high energy density per unit mass, it has exceptional specific impulse performance compared to the existing chemical propulsion method and can reduce the amount of fuel loaded, thereby having advantage for long-distance exploration. For this reason, advanced countries in space development are recently spurring to the research of nuclear propulsion technology, and it is judged that the development of a propulsion engine using nuclear power is absolutely necessary in order to gain an competitive edge on the space development.