• Journal of the Korea Institute of Military Science and Technology
• /
• v.11 no.4
• /
• pp.76-82
• /
• 2008

Alloy 718 nozzle component was manufactured by hot forging and electron beam welding process. In this process, 718 billets produced in domestic company were used and evaluated. Before performing industrial scale hot forging, small size hot compression tests were carried out under various process conditions and then microstructural evaluations were analyzed. Using the results, FEM simulations were performed in order to optimize the hot working process. After hot working, forged work-pieces were machined and welded by electron beam. Final nozzle components were heat treated and their microstructure and mechanical properties were investigated.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2008.11a
• /
• pp.305-309
• /
• 2008

This experimental study has been conducted to investigate the installation of the vertical flame holder shape in ramjet combustor, which affects on the film cooling effectiveness. All slot position, the film cooling effectiveness decreases because of the shear layer and high turbulence intensity between separated flows and coolant flows. When the flame holder is installed, film cooling effectiveness decreases abruptly on the beginning of the slot exit region due to the mixing effect. As the blowing rate increases, the film cooling effectiveness is increased for all cases due to the augmented momentum of injected coolant from the slot.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2011.04a
• /
• pp.331-334
• /
• 2011

The performance of ramjet engine is closely associated with a supersonic intake. In this study, experiments and computational simulations were conducted to observe the internal flow characteristics of the supersonic intake. The supersonic intake which have self-starting characteristics was designed and manufactured. The flow characteristics was analyzed from the experimental results using the supersonic wind tunnel testing and computational results using RANS equation and Menter's SST turbulence model. The detailed visualization results were suggested for the pseudo-shock wave of stable operations and for the inlet buzz phenomenon of unstable operations.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 1995.11a
• /
• pp.33-45
• /
• 1995

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• v.y2005m4
• /
• pp.112-115
• /
• 2005

The objectives of this study are to evaluate the dynamic fracture toughness of advance glass ceramics(MACOR glass-filled ceramic, Corning Glass Works) for dome port cover of the ramjet. Static and dynamic fracture toughness tests are performed using strain gage method in the variation of notch radii.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2005.11a
• /
• pp.450-454
• /
• 2005

A numerical analysis is performed to analyze the reacting flow-field of an axisymetric coaxial ramjet combustor. Two dimensional Navier-Stokes equation with low Reynolds number $k-\varepsilon$ turbulence model is utilized and finite-rate chemistry model is adopted. Eddy dissipation model is applied for a modeling of turbulent combustion. Two different types of combustors (combustor with a suddenly expanded dump and combustor with wedge-shaped flame holders) are compared in a view point of flame stabilizing.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2011.11a
• /
• pp.992-995
• /
• 2011

A study on the performance design schemes of the supersonic air intakes applied to the supersonic air-breathing propulsion system(Ramjet/Scramjet) was conducted and for two kinds of air intakes, the preliminary configuration designs and the performance analysis models were established. For axisymmetric conical air intake and two dimensional rectangular air intake, the performance effects were assessed according to compression angles and shock wave numbers.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2009.11a
• /
• pp.581-585
• /
• 2009

In this study, conceptual design of the RBCC (Rocket Based Combined Cycle) engine was performed for the hypersonic propulsion system development. For the flight mission, RBCC engine takes off at sea level and accelerates up to Mach 8 at the altitude of 30km. By the flight speed characteristics, operating pattern of the engine is categorized into 3 modes : Ejector jet (~Mach 3), Ramjet (Mach 3~6), Scramjet (Mach 6~8). According to the engine mode characteristics, RBCC engine design and analysis was performed.

• 한국연소학회:학술대회논문집
• /
• 2003.12a
• /
• pp.153-157
• /
• 2003

Supersonic and hypersonic aircrafts must pass wide range of speed to reach high speed region. But for existing engines the most efficient operating speed ranges are decided according to their flying speed, so an engine which mixes several engines like TRJ (Turbo Ramjet) and ARJ (Air Turbo Ramjet) has been planed. This mixed type engine has inefficiency that more than two engines must be installed simultaneously, but the pulse detonation engine (PDE) that uses detonation wave has a strong point that it can operate in all speed range with single engine. This paper deals with the simulation of the pulse detonation engine which uses hydrogen peroxide $(H_2O_2)$ mono propellant. Hydrogen peroxide is low-cost propellant, and it is reacted without oxidizer. Comparison between $H_2-O_2$ mixture with $H_2O_2$ mono propellant about thrust, pressure, temperature and velocity shows that $H_2O_2$ is a very useful propellant.

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