http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
항공기용 가스터빈의 고압 냉각 터빈 노즐에 대한 복합열전달 해석
김진욱,박정규,강영석,조진수 한국항공우주학회 2014 한국항공우주학회 학술발표회 논문집 Vol.2014 No.11
중소형 항공기용 가스터빈엔진 엔진 냉각터빈 노즐의 설계 검증을 위해 복합열전달 해석을 수행하였다. CMSX-4 소재의 고압 냉각 터빈 노즐에는 막냉각, 충돌냉각, pedestal, rib turbulator와 같은 냉각 요소들이 적용되어졌다. 입구조건에 연소기 출구 온도 프로파일을 적용하였고, 난류모델은 k-ω based SST를 사용하였다. 복합열전달 해석을 통하여 냉각 요소들의 조합에 따른 냉각 효과를 확인하였다. 베인 주변의 압력과 마하수 분포를 보고 충격파가 발생하는 지점이 흡입면의 뒷전 부근임을 확인하였다. 베인의 흡입면 앞전 영역에서 냉각 효과가 가장 낮았고 압력면 중간에서 냉각효과가 가장 높았다. 본 연구를 통해 고압 냉각 터빈 노즐의 표면 냉각 효과를 확인하였고, 그 결과를향후 고압 냉각 터빈의 냉각 설계에 반영할 예정이다. Conjugate Heat Transfer(CHT) analysis was performed to verify the design of the high pressure turbine nozzle cooling of gas turbine engine. The cooling components such as the film, impingement cooling, pedestal, rib turbulator were applied to a high pressure turbine nozzle made of CMSX-4. The combustor exit temperature profile was given to the inlet condition. The k-ω based SST turbulence model was used. The effect of the cooling components was checked through the CHT analysis. Checking the pressure and Mach number around the vane, the shock occurred at the trailing edge region of suction side. The lowest cooling effectiveness was revealed at the leading edge of suction side. At the middle of pressure side, the highest cooling effectiveness was appeared. The thermal tendency of the cooled vane surface was checked. This results will be applied at the redesign of the high pressure cooling turbine.
분사냉각모듈 내에 부착된 히트싱크에 따른 고출력 LED의 냉각성능에 관한 연구
구건모(G. M. Ku),김경진(K. Kim),박상희(S. H. Park),최성대(S. D. Choi),허정욱(J. W. Heo) 한국기계가공학회 2013 한국기계가공학회지 Vol.12 No.6
The purpose of this study is to investigate cooling performance of high power LEDs from 100 to 200 W class by using a jet impingement cooling module. The numerical analysis of forced convection cooling inside cooling module is carried out using a multi-purpose CFD software, FLUENT 6.3. In the experiments, the LED cooling system consists of jet impingement module, heat exchanger, water reservoir, and pump. In the present study, the cooling performance of jet impingement cooling module is investigated to determine the effect of the heat sink types on the impinging surface, the space and length of fins. Numerical and experimental studies show the reasonable agreement of LED metal PCB temperature between those results and give the optimized design parameters such as the space of fin and the length of fin. Also, the pin fin type of heat sink is found to be more efficient than the plate type heat sink in jet impingement cooling.
가스터빈의 연소기 냉각을 위한 이중벽 냉각 구조에서 유출 구멍의 복합각도 변경에 따른 냉각 성능 변화에 대한 수치해석적 연구
권화빈,박희성 한국전산유체공학회 2022 한국전산유체공학회지 Vol.27 No.4
For the cooling of the combustor liner, this investigation considers a double-wall cooling structure in which the compound angle and orientation angle of the effusion hole are 30° and ±30°. respectively. Also, to analyze the effect of orientation angle, data for comparison in a simple angle configuration with an orientation angle of 0° is provided. In this study, the heat transfer and flow characteristics of the double wall cooling structure by the change in orientation angle were numerically analyzed. The results of the numerical simulations was obtained using ANSYS FLUENT V 21.1 numerical codes with a shear stress transfer k–ω turbulence model. Data are provided for main flow Reynolds numbers from 142,000 to 149,000. and overall blowing ratios from 5.5 to 7.4. The use of compound and orientation angle arrangements inhibits the formation of horseshoe-shaped vortices, resulting in asymmetry of the counter rotating vortex. As a result, the lift-off of the coolant injected from the effusion holes is suppressed from the effusion cooling plate. When orientation angle is changed from 0° to ± 30°, the area-averaged film cooling effectiveness and area-averaged heat transfer coefficient increase by 7.7% and 12.4% overall, respectively. The skewed and non-symmetric shape of the horseshoe-shaped vortex is also increased by the use of orientation angle arrangement, which also provide localized improvements in surface thermal protection.