• Journal of Aerospace System Engineering
• /
• v.14 no.1
• /
• pp.1-7
• /
• 2020

This paper discusses a series of procedures and results for designing the gear part of a fuel transfer pump for an aircraft, developed as an independent technology for the first time in Korea. A gear pump type is selected because the design requirements of the fuel transfer pump are met by a gear pump with a characteristics of less leakage inside than a vane pump with superior overall performance. The gear housing is designed with suitable clearance, considering the outer diameter of the gear, which is the main factor on which the flow can be determined. Additionally, the calculation of the required hydraulic and axial force for the motor to drive the fuel transfer pump was performed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 1998.04a
• /
• pp.6-6
• /
• 1998

중형항공기용 터보팬 엔진의 정상상태 및 천이상태 성능을 해석하고 제어기 설계를 위한 선형모델을 구하였다. 정상상태 성능해석은 설계점으로 선정한 지상정지조건과 최대상승조건(Mach=0.78, 고도=36000ft) 및 순항조건(Mach=0.78, 고도=39000ft)을 고려하였으며, 저압압축기의 공회전 상태에서 최대 회전속도까지의 부분부하성능해석을 수행하였다. 부분부하 성능해석 결과 90% RPM 조건에서 가장 연료소모율이 적어 경제적임을 알 수 있다. 동적 성능모사는 각각의 대기조건에서 연료가 Step 증가, Ramp 증가 및 감소, Step 증가 후 Ramp 감소하는 경우에 대해 수행하였다. 모사결과 고려된 모든 조건에서 연료의 Step 증가시 고압압축기의 터빈입구온도가 제한온도를 초과하여, 보다 빠른 가속과 최적의 성능을 위해서는 적절한 제어가 필요함을 알 수 있었다. 또한 최대상승조건에서 연료를 Step 증가시킬 경우 고압압축기에서 실속이 발생하여 이에 대한 대책도 필요함을 알 수 있었다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2013.10a
• /
• pp.232-235
• /
• 2013

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 1998.10a
• /
• pp.37-37
• /
• 1998

중형항공기용 터보펜 엔진의 성능모사와 LQR 제어기 설계에 대한 연구를 수행하였다. 동적 성능모사를 설계점으로 선정한 지상최대이륙조건과 탈설계점으로 선정한 최대상승조건과 순항조건에 대하여 Step 증가, Ramp 증가, Ramp 감소, Step증가 후 Ramp 감소의 4가지 연료공급에 조건에 대하여 수행되었다. 성능모사 결과 모든 비행조건에서 연료를 Step 증가시킬 경우 고압터보빈의 입구온도가 제한온도인 3105$^{\circ}$R을 초과함을 확인하였고, 최대 상승조건에서 연료를 Step 증가시킬 경우가 4.5초 이내에 Ramp 증가시킬 경우 고압압축기에 서지가 발생함을 확인하였다. 따라서 고압터어빈의 오버슈트와 고압압축기의 서지를 동시에 제어할 수 있는 다변수 제어기의 설계가 필요함을 확인하였다.

• The KSFM Journal of Fluid Machinery
• /
• v.11 no.2
• /
• pp.82-88
• /
• 2008

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.7
• /
• pp.687-693
• /
• 2016

The rapid turning and acceleration movement of a rotorcraft leads to a sloshing phenomenon in the fuel tank. Sloshing caused by rapid movement can affect the internal components by creating an excessive load. In severe situations, the resulting damage to the internal components and pipes can also lead to the tearing of the fuel tank itself. Therefore, to improve the survivability of the crew, the internal components of the fuel tank must be designed to retain their structural soundness during the sloshing phenomenon. In order to accomplish this, the sloshing load acting on the components first needs to be determined. This paper investigates the sloshing load applied to the internal components by performing numerical analysis for rotary-wing aircraft fuel tanks in the sloshing test. Fluid-Structural Interaction (FSI) analysis based on smoothed particle hydrodynamics (SPH) is conducted and the conditions specified in the US military standard (MIL-DTL-27422D) are employed for the numerical simulation. Based on this numerical simulation, by analyzing the load applied to the internal components of the fuel tank due to the sloshing phenomenon, the possibility of obtaining the design data by numerical analysis is examined.

• Aerospace Engineering and Technology
• /
• v.11 no.1
• /
• pp.84-90
• /
• 2012

Fuel shutoff valve of a combustion chamber controls propellant mass flowrate of a rocket engine, by using pilot pressure and spring force. The developing fuel shutoff valve can be self sustained even though pilot pressure is removed in an actuator. Therefore, it is necessary to analyze the characteristics of the forces with respect to the opening and closing of the valve in order to evaluate its performance. In light of this, the valve has been designed to adjust the control pressure for the opening of the poppet and to determine the working fluid pressure at which the valve starts to close. This paper also has been predicted flow coefficient of the valve by Fluent(ver. 12.0) CFD analysis. Various results from the prediction and the analysis have been compared with experiments.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.3
• /
• pp.1054-1060
• /
• 2013

Fuel tank of a rotorcraft has a great influence on the survivability of crews. For a long time, US army has tried to develop the proper material for fuel cell of a military rotorcraft. As a result, the design specification of fuel cell, MIL-T-27422A, was issued for the first time on 1961. Through a few revisions, it has been developed to ML-DTL-27422D in 2007. It should be assured that fuel cell satisfies the requirement defined in MIL-DTL-27422D. The qualification test of this specification is classified into Phase I test for material and Phase II for fuel cell itself. This paper studies test conditions and procedures of slosh & vibration, gunfire resistance and crash impact test. They are considered as the most important tests which have a high possibility of failure. The rational consideration of this paper can improve the ability for estimating not only the validity of test procedure and test condition but test result. Based on the rational consideration, it is expected that the ability of the systematic development can be improved.

• Journal of Aerospace System Engineering
• /
• v.18 no.1
• /
• pp.64-71
• /
• 2024

The external fuel tank of an aircraft is a main component that can increase the cruising range of the aircraft. It must be able to be stably separated from the pylon in an emergency situation. At this time, a separation load is applied to the fin and the pivot of the external fuel tank. To stably separate the external fuel tank, the structural soundness of the fin and the pivot must be confirmed. In this study, structural tests were conducted to verify the structural integrity of the external fuel tank pin and pivot when the external fuel tank was separated from the aircraft. Results are then presented. In this paper, a test configuration diagram consisting of the hydraulic and load control equipment, data acquisition system, and pneumatic supply unit used in the structural test was explained. Test installation and test load application plan for each test condition were provided. As results of the structural test, it was found that test load and internal pressure of the test specimen were properly controlled within the allowable range in each test. It was confirmed that serious structural defects in the test specimen did not occur under required load conditions. In conclusion, through structural test for design limit load and design ultimate load, it was proven that the fin and pivot of the external fuel tank for aircraft covered in this study had sufficient structural strength.

• Proceedings of the KAIS Fall Conference
• /
• 2010.05b
• /
• pp.1173-1176
• /
• 2010

회전익 항공기의 연료탱크는 피탄으로 인해 연료 누유시 발생할 수 있는 화염으로부터 기체와 승무원의 생존성을 높이기 위하여 연료누설을 차단하는 자기밀폐 기능이 필수적으로 요구된다. 자기밀폐 기능은 내부에 적층된 자기밀폐 소재가 누설되는 연료와 화학반응을 일으켜 급속히 팽창됨으로써 피탄부를 막아, 연료누설을 차단하는 역할을 한다. 본 연구는 미군사규격(MIL-DTL-27422D) 기준으로 국내에서 제작 및 수행한 회전익 항공기의 연료탱크 자기밀폐 성능시험 평가 결과를 제시한다.