• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2010년 춘계학술대회논문집
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• pp.258-262
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• 2010

Since MEMS based micro actuators or generating devices showed high efficiency per volume, plenty of research are ongoing. Among them, MEMS based millimeter-scale micro gas turbine is one of the most powerful item for replacing chemical batteries. However, due to MEMS manufacturing technique, it is very difficult that makes wide turbine bearing area. It causes low DN number, so sufficient bearing force is hard to achieve. Thus, the most important issue on micro gas turbine is to design the proper bearing which can keep rotor stable during operation. In order to that, micro-scale gas-lubricated bearing is generally used. In this paper, basic feasibility study of thrust bearing of 10mm diameter turbine is described. Thrust bearing is hydrostatic gas-lubricated type. Numerical simulation is performed with ANSYS CFX 11.0 which is commercial numerical tool. Relationship between bearing inlet pressure and mass flow rate and bearing force is figured while changing bearing gap and number of capillaries. The simulation results will be used for further design of micro gas turbine.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2011년 춘계학술대회논문집
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• pp.387-391
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• 2011

Since MEMS based micro actuators or generating devices have high efficiency per volume, plenty of research are ongoing. Among them, MEMS based millimeter-scale micro gas' turbine is one of the most powerful issue for replacing chemical batteries. However, since limiting of MEMS manufacturing technique, it is very difficult that makes wide turbine bearing area. It causes low DN number, so sufficient bearing force is hard to achieve. Thus, the most important issue on micro gas turbine is proper bearing design which can keep rotor stable during operation. In order to that, micro-scale gas-lubricated bearing is generally used. In this paper, basic feasibility study and design of journal bearing for 10mm diameter micro gas turbine is described Journal bearing is hydrostatic gas-lubricated type. Numerical simulation is performed with ANSYS CFX 11.0 which is commercial numerical tool. Repulsive force when there is radial displacement in bearing and returning time is calculated using steady and unsteady cases. Auto re-meshing technic is used for moving mesh unsteady cases which simulate displacement of axis and its movement. The simulation results are used for further design of micro gas turbine, and experiment will be done later.

• 한국유체기계학회 논문집
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• 제19권1호
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• pp.24-30
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• 2016

In this study, a 2W micro-gas turbine engine was designed using micro-electro-mechanical systems (MEMS) technology, and experimental investigations of its potential under actual combustion conditions were performed. A micro-gas turbine (MGT) contains a turbo-charger, combustor, and generator. Compressor and turbine blades, and generator coil were manufactured using MEMS technology. The shaft was supported by a precision computer numerical control (CNC) machined static air bearing, and a permanent magnet was attached to the end of the shaft for generation. A heat transfer analysis found that the cooling effect of the air bearing and compressor was sufficient to cover the combustor's high temperature, which was verified in an actual experiment. The generator performance test showed that it can generate 2W at design rotational speed. Prototype micro-gas turbine generated maximum 1 mW electric power and lasted up to 15 minutes.

• 대한기계학회논문집B
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• 제34권9호
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• pp.835-841
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• 2010

MEMS 가스터빈 엔진에서 연료와 공기의 혼합에 영향을 미치는 중요한 요소중 하나는 연료 분사구 형상의 설계이다. 본 연구에서는 3 개의 연료 주입부와 각 주입부에 연결된 여러 개의 분사구에 의해 연료와 공기가 혼합되는 시스템을 고려하여 분사구의 배열과 연료 공급비율의 변화에 따른 혼합 정도를 당량비를 통하여 정량적으로 해석하였다.

• 대한기계학회논문집B
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• 제39권2호
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• pp.153-159
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• 2015

본 연구에서는 MEMS기술을 적용한 2W급 초소형 가스터빈엔진의 개발과 실제 연소 환경에서의 발전 가능성을 해석적, 실험적으로 입증하였다. 초소형 가스터빈엔진은 터보차저, 연소기, 발전기로 이루어져 있다. 터보차저는 각각 직경 10mm와 9mm의 MEMS 공정 압축기와 터빈으로 구성되어 있으며 발전코일 또한 MEMS공정으로 설계되었다. 제작된 압축기와 터빈은 정밀 기계 가공된 축과 공기 베어링으로 지지되고 회전하며, 회전축 끝단에 영구자석을 설치하여 발전을 하게 된다. 공기 베어링과 압축기를 통한 냉각 효과를 해석하여 연소기에서 발생한 열을 충분히 차단할 수 있는 것으로 분석되었고, 이를 실험을 통해 검증하였다.