• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.11
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• pp.70-75
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• 2006

The cabin pressurization system response should be consistent with the design limits such as the cabin pressure schedule, the pressure regulation tolerance, the maximum rate of pressure change during normal and abnormal operation and the maximum cabin air inflow rate change. In this paper, the results of pressure loss analysis and flight test for cabin pressurization system of T-50 advanced trainer are introduced. The pressure tolerance at unpressurized condition using calculated exit area of pressurization components through pressure loss analysis is predicted. Pressurization components of D company are selected and the predicted pressure tolerance is in good agreement with flight test results. Finally, T-50 pressurization system is verified by some flight tests of T-50 advanced trainer to comply with various pressurization design criteria of MIL-E-18927.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.40 no.1
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• pp.49-57
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• 2011

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.5
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• pp.170-175
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• 2013

For this study, the domestically developed bootstrap reservoir of the aircraft is set up in accordance with the temperature and humidity conditions depicted on the qualification test, and the variation in the internal pressure of the bootstrap reservoir of the aircraft is examined. The study shows that the bootstrap reservoir has less variation in the internal pressure at room temperature than at low temperature($-40^{\circ}C$). As a result, the internal pressure can be maintained stably when the temperature of working fluid in the bootstrap reservoir and the atmosphere environment is over room temperature($25^{\circ}C$). Therefore the keeping of temperature above room temperature is very important to operate the bootstrap reservoir of the aircraft properly.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1709-1714
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• 2004

Pressurization system of a 50m unmanned airship was manufactured according to the detailed design. In this paper. the whole procedures including system design. simulation and fabrication were described. The fabricated part were ground tested to check compliances with design requirements. Ground tests include operational tests, leakage tests, endurace tests and low temperature environmental tests. Results shows pressurization system of a 50m unmanned airship meets design requirements. Currently. pressurization system is installed to the KARI airship, Via 50m and performance verification through the flight tests are being conducted.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.3
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• pp.230-236
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• 2018

This paper deals with the improvement of pressurized quality for high maneuver aircraft. Anti-G Valve is a pressure regulating valve for inflating anti-G suits and providing a sense line signal for a g-compensated oxygen regulator. The new anti-g valve system is satisfied with military specification MIL-V-87255 and allowed the pilots to tolerate high-G exposures without any vibrations. The flight test was performed by two T/FA-50 pilots and other tests used the centrifuge made by anti-g developer. A comparison of the new anti-g valve with period one, it have better response and low chattering phenomenon.

• Journal of the Korean Society for Railway
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• v.10 no.6
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• pp.723-729
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• 2007

The Ministry of Environment established a guide line in December 2006, "Indoor Air Quality Management guidelines in Public Facilities." As the items of the guideline, $CO_2$ (Carbon dioxide) and PM10 (particulate matter) is shown to Level 1 and 2. Therefore trains and subways are included. There are a lot of tunnels by the lay of mountains on KTX (Korean Train Express) service. HVAC (Heating Ventilating and Air-conditioning)-pressurization equipment on KTX is various functioning flaps blocking outside pressure waves. At that time, the fresh air is blocked by flap operation and the air is circulated by return air. In this study, we measured the time series of $CO_2$ and PM10 concentrations in the KTX passenger cabin during the train service of Gyongbu line (Seoul-Busan) and Honan line (Yongsan-Mokpo) from July 2006. Also, analyzed the air quality by operation of KTX HVAC-pressurization equipment in tunnel passing point. As a result, PM10 concentration was totally lower than the regulation values. However, $CO_2$ was highly correlated with several tunnels, such as Oksan-Otan, Godeung-Hyudae and Gaechak-Iijik tunnel. but, the indoor air quality of KTX train have been proved satisfy the recommendation the Ministry of Environment guidelines.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.11
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• pp.963-968
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• 2003

A feedback control implementation for a high speed train pressurization system is proposed based on CAN (Controller Area Network). Firstly, system model including network latencies by CAN arbitration mechanisms is proposed, and an analytical compensation method of control parameters based on the system model is proposed for the network latencies. For the practical implementation of the control, global synchronization is adopted for controller to measure network latencies and to utilize them for the compensation of the control parameters. Simulation results are shown with practical tunnel data response. The proposed method is evaluated to be the most effective for the system through the control performances comparing among a controller not considering network latencies, other two off-line compensation methods, and the proposed method.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1384-1387
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• 2003

Pressurization test is usually required in aircraft full-scale static test. There are several test conditions including pressurization of cockpit, fuselage fuel tank, air inlet duct for T-50 full-scale static test. In this paper, the test conditions, equipment, piping analysis for the pressurization test are introduced. Tank simulation test is performed to verify the validity of piping analysis and to find good tuning parameters for the pressurization channel in the servo controller. Several test setup for pressurization of T-50 test is introduced. Test article volume is filled by form, $60%{\sim}80%$ volume is reduced for the T-50 full-scale static test. Pressurization system is connected to servo controller which also controls hydraulic actuator. Load and pressure control is synchronized by using the same servo controller during T-50 test. Typical control result for pressurization test condition is shown. Pressurization tests of T-50 full-scale static test was completed successfully.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2445-2447
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• 2002

In this paper, CAN-based feedback control system is proposed for the pressurization system of korean high-speed train. The control performance of the system is evaluated. According to the requirement of the pressurization system A process model considering network delay and an adaptive PID control method based on the process model are proposed here. And it is shown that the proposed adaptive PID control method considering the network delay has on adequate feature compared to some other existing methods consequently it can be considered to be applied the pressurization system of korean high-speed train.

• Proceedings of the KSR Conference
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• 2002.10a
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• pp.162-167
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• 2002

열차가 고속으로 터널에 진입하게 되면 터널 내부에서 극심한 압력 교란이 발생하게 되며 이로 인한 이명현상은 승객들에게 불쾌감을 크게 유발시키고, 열차 구조물에 작용하는 반복적인 하중변화 또한 구조상 큰 문제를 일으킬 수 있게 된다. 따라서 이를 해결하기 위해서는 터널 내부의 유동장에 대한 정확한 예측이 필요하다. 본 논문은 긴 터널을 효율적으로 해석하기 위해서 최소 차원의 공간 가정을 통하여 계산 시간을 절약할 수 있는 혼합차원 기법을 이용하여 현재 G7 시제차의 시험 운행 구간내의 터널들에 대해서 수치해석을 수행하였다. 해석 결과 터널 내부에서는 압축파, 팽창파의 상호 작용에 의한 복잡한 압력 교란이 발생하였고, 이러한 압력 변화는 열차 속도, 터널 길이, 측정위치에 따라 각각 다르게 나타났다. 따라서 터널 내부의 유동장을 정확히 예측하려면 열차 속도, 터널 길이, 열차 길이, 열차/터널 단면적 비, 측정 위치 등을 고려하여 해석을 수행하여야 한다. 이러한 수치 해석 결과는 시제차 시험 계획의 수립 및 시험기기의 선택과 설치 위치 등을 결정하는 중요한 자료로 활용될 수 있을 것이며, 고속 열차의 여압 시스템과 외부 부착 구조물에 대해서도 중요한 정보를 제공할 수 있을 것이다.