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차봉준,임병준,양수석,이대성,Cha, Bongjun,Lim, Byungjun,Yang, Sooseok,Lee, Daesung 한국유체기계학회 2001 한국유체기계학회 논문집 Vol.4 No.1
The experimental study on the effect of axial clearance between the tip of impeller blades and stationary shroud has been performed. The investigated compressor, which is a part of a small auxiliary power unit engine, consists of a curved inlet, a centrifugal impeller, a channel diffuser and a plenum chamber. It was designed for a total pressure ratio of 4.3 and an efficiency of $77\%$ at design speed of 60,000 rpm. The experiments are carried out in an open-loop centrifugal compressor test rig driven by a turbine. For the four different clearance ratios Cr(clearance/impeller tip width) of 6.25, 10.93, 15.60 and 20.30 percent, the overall performance data are obtained at $97\%,\;90\%$ and $80\%$ of the design speed. The results show the overall pressure ratio decrease of $7.7\%$ and the efficiency loss of $8.7\%$ across the variation of clearance ratio near the design speed. It also indicates that the influence of tip clearance became weaker as the flow rate is reduced and the stable operating range is not significantly influenced by the change of clearance ratio.
김진한,최창호,김춘택,양수석,이대성,Kim, Jin-Han,Choi, Chang-Ho,Kim, Chul-Taek,Yang, Sooseok,Lee, Daesung 한국유체기계학회 2001 한국유체기계학회 논문집 Vol.4 No.1
In developing a multistage compressor, the stage matching is one of the critical design issues. The mismatching can be often observed even if each stage has been proven good and then used as part of a compression system. A good matching among the stages can be achieved by changing various design parameters (i.e., passage cross sectional areas, blades angles, stagger angles, curvature, solidity, etc.). Therefore, designers need to find out what parameters must be changed and how much. In this study, a method to search the design parameters for optimum stage matching has been used based on an 1-D mathematical model of a compressor, which uses the data obtained from the preliminary test to identify the design parameters. This methodology is applied with a two-stage axial compressor, which was originally designed for a helicopter gas turbine engine. After identifying design parameters using preliminary test data, an optimization process has been employed to achieve the best matching between the stages (i.e., maximum efficiency of the compressor at its operation modes within a given range of the rotor speed under given restrictions for required stall margins and mass flow). 3-D flow calculations have been performed to confirm the usefulness of the corrections based on the 1-D mathematical model. Calculational results agree well with the experimental data in view of the performance characteristics. Some promising results were produced through the methodology proposed in this paper in conjunction with flow calculations.
조남경(Namkyung Cho),양수석(Sooseok Yang) 한국추진공학회 2023 한국추진공학회지 Vol.27 No.5
Nuclear space propulsion has the advantage of superior specific impulse compared to the currently widely used chemical propulsion, the system can be simplified by omitting the oxidizer system, and has the ability to improve performance in the future. The high specific impulse makes missions that are only possible with large chemical propulsion launch vehicles possible with medium-sized launch vehicles. This paper describes the characteristics of nuclear propulsion that are different from chemical propulsion and introduces the nuclear propulsion system and key components. Nuclear thermal propulsion and electric propulsion, and a bimodal system and a hybrid system that combines chemical propulsion and nuclear propulsion are introduced. Also, the development aspects of nuclear propulsion as well as test facility and launch safety of the nuclear power propulsion system are discussed.
습도 영향을 고려한 초소형 터보제트 엔진 성능시험 소개
이보화(BoHwa Lee),이경재(KyungJae Lee),양수석(SooSeok Yang),김유일(Yuil Kim) 한국추진공학회 2010 한국추진공학회 학술대회논문집 Vol.2010 No.11
대기 중의 수증기는 가스터빈엔진의 주요성능에 많은 영향을 끼친다. 습공기의 영향은 기온 및 기압이 높은 여름철 해면 고도, 높은 비행 마하수 그리고 낮은 엔진 회전수에서 그 영향이 더욱 두드러진다. 이러한 습공기 유입에 따른 가스터빈 엔진의 성능변화의 정도를 살펴보고자 200lbf 급 초소형 터보제트 엔진의 고공환경 성능시험을 통해 습도가 엔진성능에 미치는 영향에 대하여 알아보았다. 고공환경 엔진시험을 통해, 건공기 유입에 비해 습공기 유입 시 순추력에서 2.826% 낮게, 비연료소모율에서 1.325% 높게 측정되었다. The moisture in the atmosphere exerts a lot of influence upon Gas turbine engine performances. There is a noticeable influence of wet air at the summer sea level, high flight mach number and low engine rpm increasingly. An altitude Engine Test Facility is used to accomplish the engine performance tests at dry air condition and wet air condition, through which engine performance results is revealed. In the result, net thrust and specific fuel consumption measured -2.826% and 1.325%, respectively at wet air condition compared to dry air condition.
이보화(BoHwa Lee),박부민(Poomin Park),양수석(SooSeok Yang) 한국추진공학회 2010 한국추진공학회 학술대회논문집 Vol.2010 No.11
태양전지, 연료전지, 이차전지와 같은 동력시스템을 사용하는 EAV2 전기비행기의 특정 비행 전 구간에서 걸쳐 필요한 추진요구전력에 대한 분석을 수행하고, 이를 통해 비행영역에서 최적의 추진시스템 무게로 공급가능전력에 대한 동력 시나리오를 논의하였다. 그 결과 길이 6m, 폭 0.35m의 글라이더형 전기추진비행의 위해서는 최적의 추진시스템 무게는 7.06kg이며, 연료전지 500W와 이차전지 100W의 전력으로 비행가능함을 알 수 있었다. A study on the required propulsion powers at the EAV2 electric propulsion vehicle using power system such as solar cell, fuel cell and secondary cell is conducted, through which the scenario about available supply power is discussed at the optimum propulsion system weight on the specified flight envelope. In the result, it is noticed that propulsion system weight is 7.06kg and fuelcell 500W and secondary cell 100W are available to flight for glider-type electric vehicle with 6m length, 0.35m width.