• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2010.11a
• /
• pp.410-415
• /
• 2010

The engine ground and altitude tests were carried out to investigate the effect of jet fuel alteration on the performance of a small turbojet engine. JP-S was supplied 8% higher than JP-8 by fuel metering system at the same command. The employment of JP-S showed the similar starting characteristic to that of JP-8, however, difference in the ignition time and acceleration rate of engine speed due to the difference of fuel flow rate by fuel metering system was observed. In spite of jet fuel alteration, the test results yield the similar Steady-State engine performance in Net thrust, Air flow, Exhaust Gas Temperature, etc. On the other hand, the Fuel consumption of JP-S increased by 5 % compared with that of JP-8. In point of Specific Fuel Consumption (SFC), SFC of JP-S was approximately 1.1~2.6 %, 5 % higher than that of JP-8 in ground and altitude tests respectively at the same thrust.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.15 no.2
• /
• pp.23-28
• /
• 2011

The engine ground and altitude tests were carried out to investigate the effect of jet fuel alteration on the performance of a small turbojet engine. JP-S was supplied 8% higher than JP-8 by fuel metering system at the same command. The employment of JP-S showed the similar starting characteristic to that of JP-8, however, difference in the ignition time and acceleration rate of engine speed due to the difference of fuel flow rate by fuel metering system was observed. In spite of jet fuel alteration, the test results yield the similar steady-state engine performance in net thrust, air flow, exhaust gas temperature, etc. On the other hand, the fuel consumption of JP-S increased by 5 % compared with that of JP-8. In point of specific fuel consumption (SFC), SFC of JP-S was approximately 1.1~2.6 %, 5 % higher than that of JP-8 in ground and altitude tests respectively at the same thrust.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.10 no.1
• /
• pp.38-43
• /
• 2006

In the present study, preliminary design and analysis for a jet pump, which is able to transfer fuel from the tank to the engine, were performed as an aerospace component technology development project. The jet pump is a core part, which is normally installed in the fuel tank, to supply the fuel from the tank to the engine feed pump, or to transfer the feed between tanks. In order to design preliminarily installed in the jet pump, equations for design were modelled using SIMULINK, and the design was carried out based on the simulation model.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.35 no.11
• /
• pp.1013-1021
• /
• 2007

Design and performance analysis of the jet pump to transfer fuel between tanks in the smart UAV fuel supply system were carried out through one dimensional flow analysis and the flow analysis using a commercial CFD code. From the analysis results, it was proved that the jet pump was designed with the flow ratio of 2.23 that is the fundamental requirement of the jet pump design. The comparison results showed that the primary nozzle pressure is higher in the CFD analysis than in one dimensional flow analysis, mainly due to the underestimated loss coefficient of the primary nozzles. Consequently, the loss coefficients of the jet pump components should be determined more precisely for the design of the jet pumps with high performance.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.37 no.1
• /
• pp.67-74
• /
• 2013

A jet in a crossflow (JICF) has been extensively studied because of its wide applications in technological systems, including fuel injection into a ram-combustor. However, in the case of insufficient mixing performance of the liquid jet into the crossflow, the flame in a ram-combustor is unstable. In this study, the nonuniform flame and combustion instabilities due to lack of mixing performance were experimentally investigated. By performing correlations to predict the penetration height and break-up point, the spray and mixing characteristics of JICF have been studied. In particular, the improved correlations of penetration height are proposed in two distinctive domains depending on the X/d location of the crossflow.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.21 no.6
• /
• pp.83-90
• /
• 2017

Performance analysis of the turboshaft engines for combined rotorcraft was executed. A tip jet and a ducted fan aircraft were selected for combined rotorcraft application. Gasturb 12 software was used for turboshaft engine performance analysis. In the results, maximum required power for the tip jet engine is about 1,600 hp class and maximum required power for the ducted fan engine is about 1,000 hp class at the required aircraft mission. This is due to the additional power of the auxiliary compressor to get a bleed air mass flow rate for the tip jet operation. At the same time, fuel consumption of the tip jet aircraft is 2.8 times larger than ducted fan case. Therefore ducted fan type aircraft is more efficient than tip jet aircraft in terms of fuel economy.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.26 no.1
• /
• pp.1-11
• /
• 2022

In a gas turbine, fuel is exposed to a high temperature environment until it is fed to the combustor through the injector. Hydrocarbon fuels can coke under high temperature conditions, which can cause coking material to deposit on fuel lines or block the injector passages. In this study, a specimen simulating a fuel line located inside a gas turbine and Jet A-1 were heated using electric devices. Jet A-1 coking tests were performed by changing the wall temperature of the stainless steel specimen and the temperature of Jet A-1 supplied to the specimen. After the coked specimens were cut, the coking material and the inner surface were analyzed using an energy dispersive X-ray spectrometer and a field emission scanning electron microscope.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.30 no.5
• /
• pp.118-126
• /
• 2002

The Altitude Engine Test Facility(AETF) was built at the Korea Aerospace Research Institute and has been being operated for the gas turbine engines in the class of 3,000 lbf thrust. To enhance the confidence level of AETF to the international level, a series of studies and facility modification have been conducted to improve the measurement uncertainty and reliability. In this paper, some part of the facility evaluation tests performed with a single spool turbojet engine are introduced. Tests were performed simulating the flight conditions as steady state, sea level for various flight speeds (i.e., Mn=0.3, 0.5, 0.7, 0.9). The obtained test results are compared with the predicted values of the engine DECK. The measurement uncertainties of airflow, net thrust, fuel flow and SFC showed 0.791~0.914%, 0.851~1.706%, 1.372~7.348% and 1.642~5.205%, respectively. Thus, from this research, the improvement methods of uncertainties on AETF has been confirmed.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.6 no.1
• /
• pp.47-54
• /
• 2002

This paper presents the results of an experimental investigation on the combustion of single droplets and 1-D droplet arrays of jet A-1 fuel droplets in atmospheric pressure. Experimental results indicate that burning rate constants$({\kappa}_c)$ of jet A-1 fuel droplets were independent of initial droplet size as $0.915{mm}^2$/sec. It was acquired a general relationship expressing the variation of $d^2$ with time for droplet burning For 1-D droplet arrays $(l/d_o$=1.208{\sim}2.922)$/TEX>, the burning rate constant ${\kappa}_c$ decreased with decreasing droplet spacing $l/d_o$ and, The effect on combustion rate constant ${\kappa}_c$ was stronger to second fuel droplet than third fuel droplet with uniform droplet distance

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.31 no.4
• /
• pp.82-91
• /
• 2003

Experiments to investigate the mixing performance of unlike doublet impinging jets are conducted. Reynolds number of simulants used in this study rages from 1.0 to 1.5 Cold flow test is performed to investigate the hydrodynamic effect and spray of the impinging jets are collected locally and calculated by using Rupe's mixing efficiency equation. Momentum exchanges and relative velocity ratio between two jets are taken as the main parameter to represent the effect of enlargement of the orifice diameter. As diameter ratio increases, the corresponding momentum ratio where maximum mixing efficiency occurs and relative velocity at the maximum mixing efficiency ranges 0.6 to 0.7, respectively. Penetration depth can be taken as a prominent parameter to estimate the mixing efficiency.