• Journal of Aerospace System Engineering
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• v.17 no.6
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• pp.72-81
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• 2023

Hydrogen-fueled gas turbines are a promising technology that can resolve the carbon dioxide emission issue as future aviation propulsion engines and carbon-free power generations. To achieve high efficiency and stability of gas turbines using 100% hydrogen as fuel, an innovative design of combustor systems is necessary to consider the characteristics of hydrogen, which are different from those of conventional hydrocarbon fuels. Micromix is a combustor design method, which aims to terminate the reaction quickly by intense mixing of fuel and air, consequently reducing NOx and increasing the stability. In this paper, we examine the principles and design process of micromix combustors as a pure-hydrogen combustion technology, and we introduce a design of a 30 kW micromix hydrogen combustor for research.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.30 no.3
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• pp.165-173
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• 2007

A space launch vehicle system represents a typical example of large-scale multi-disciplinary systems, consisting of subsystems such as mechanical structure, electronics, control, telecommunication, propulsion, material engineering etc. A lot of cost is required to develop the launch vehicle system. A precise planning of R&D cost is very essential to make a success of the launch vehicle development program. Especially in the early development phase of a new space launch vehicle system, cost estimation techniques and analogy from past similar development data are very useful methods to estimate a development cost of the launch vehicle system. Now Korea Aerospace Research Institute is in charge of the KSLV-I (Korea Space Launch Vehicle-I) Program that is a part of Korea National Space program. KSLV-I Program is a national undertaking to develop launch capabilities to deliver science satellites of a 100kg-class into a low earth orbit. It is hereafter, going to plan to develop a new korean space launch vehicle. In this paper, first the development costs of well-known launch vehicles in the world are presented to provide a reference to make a development plan of a new launch vehicle. Second this paper introduces the present status of cost estimation applications at NASA. Finally this paper presents the results from application of a TRANSCOST, a parametric cost model, to derive a cost estimate of a new launch vehicle development, as an example.

• Journal of Aerospace System Engineering
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• v.11 no.5
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• pp.56-64
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• 2017

A high altitude long endurance aircraft which carries out missions of environmental research communication relay or ground surveillance, should have the capacity to cruise in the stratosphere at a relatively low speed for a long dwell time without the necessity of refueling. When one considers the propulsion system for such an aircraft, a reciprocating engine with a serial turbo-charger system to boost rarefied ambient air up to sea level condition, would represent an good, informed and practical choice regardless of the cruising altitude of the aircraft. In this paper, high altitude long endurance aircraft developed by overseas research groups and research trends, regarding multi-stage turbocharger systems, are introduced.

• Aerospace Engineering and Technology
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• v.2 no.2
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• pp.157-166
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• 2003

IPPT(Integrated Propulsion Performance Test)s were carried out as a final stage of KSR-III(Korea Sounding Rocket-III) propulsion system development three kinds of engine with different injector faceplate were tested, therefore a engine with composite baffle was certified for a KSR-III launcher. Though a engine with STS baffle which was designed for verification of combustion instability suppression ability was not final design, due to the combustion tests with this engine, it can be described that baffle has capability to suppress combustion instability at ignition and at mainstage in the case of KSR-III combustor.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.3
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• pp.34-39
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• 2014

A study is analyzed on the design factor of center-body diffuser and performed on conceptual design of center-body diffuser with computational fluid dynamic. The flow field of center-body diffuser is calculated using axisymmetric two-dimensional Navier-Stokes equation with $k-{\epsilon}$ turbulencemodel. The center-body diffuser is compared with second throat exhaust diffuser in terms of starting pressure, the degree of vacuum pressure and the design factors. The counter flow jet on cone-tip of the center-body is applied for thermal protection system in the center-body diffuser.

• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.6
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• pp.108-119
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• 2020

Dynamic pressure sensor used in liquid rocket engine combustor and gas turbine is recess-mounted usually because it should work in high temperature environment. Although recess-mounted method can protect it from combustion gas in high temperature, tube resonance occurs in a tube-cavity system. To reduce it, the infinite tube probe(ITP) was introduced in this study. The ITP model suggested in previous literature was validated with experimental data and frequency response characteristics were analyzed. Guidelines for designing the ITP were suggested as frequency response profiles varied with geometric information and physical properties using this model.

• Journal of the Korean Society of Propulsion Engineers
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• v.26 no.5
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• pp.1-10
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• 2022

For Cu-Cr alloy developed for rocket engines, estimated fatigue lives were calculated using various fatigue life prediction methods and compared with fatigue life acquired from low-cycle fatigue tests. The utilized methods for fatigue life prediction are as follows: Coffin-Manson relation, plastic/total strain energy density relations, Smith-Watson-Topper relation, Tomkins relation, and Jahed-Varvani relation. As results of estimation of fatigue lives, it satisfied within scatter band two compared to the test fatigue lives in all methods. The quantitative calculation of the deviation of predicted fatigue lives gives that the total strain energy density relation presents the best result.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.3
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• pp.69-78
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• 2010

Korea Aerospace Research Institute started on design and development of a hypersonic air-breathing engine test facility from 2000 and completed the test facility installation in July 2009. This facility, designated as Scramjet engine test facility(SeTF), is a blow-down type high enthalpy wind tunnel which has a pressurized air supply system, air heater system, free-jet test chamber, fuel supply system, facility control/measurement system and exhaust system. In this paper, details of the specifications, and configuration of the SeTF are described. For verifying characteristics of the SeTF, wind tunnel tests are now on progress and some of the data are also described.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.4
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• pp.50-58
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• 2016

Korean Space Launch Vehicle (KSLV-II) Propellant Supply System charges liquid oxygen and kerosene to each propellant tank for the stages. To charge the launch vehicle propellant tank safety, the propellant charge flow rates and scenarios should be defined. First, the Propellant Supply System was modeled with 1D flow analysis program. The control valve capacity and orifice size were calculated by performing the 1D steady state simulation. Second, the 1D transient simulation was performed by using the steady state simulation results. As propellants were being charged at the each tank, the increased tank liquid level decreases the charge flow rate. Consequently, the proposed supply system satisfies the required design charging conditions.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.3
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• pp.127-137
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• 2021

The launch complex(LC) is composed of various facilities. The launch control system that operates remotely those of LC spends much time and labor for developing and verifying its control algorithms. The verification of algorithms is performed by the software developer entering simulated state values based on the test procedure and checking the output result according to the algorithm flow. These verification processes should be performed repeatedly, thus the human errors are easily occurred. In this paper, an efficient automated verification method with a script test procedure is proposed to minimize human errors and shorten the verification duration. We also present the results of the algorithm verification tests for the cases of the compressed gases supply system and the electro pneumatic panel system of LC.