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S-duct 흡입구 유로 형상 변화에 따른 엔진 입구면 유동 왜곡에 대한 정량적 평가
조낙원(Nakwon Jo),송지한(Jihan Song),윤준용(Joonyong Yoon) 한국추진공학회 2023 한국추진공학회 학술대회논문집 Vol.2023 No.5
This study aims to derive an S-duct shape suitable for a subsonic aircraft by quantitatively evaluating the flow distortion on the engine AIP(aerodynamic interface plane) according to the variation of the S-duct intake geometry. The S-duct is installed in front of the engine to supply stable air flow to the turbofan engine, but the airflow reaching the AIP cause flow distortion due to the S-duct shape. A severe distortion can cause engine surge. Therefore, precise evaluation of flow distortion is essential. In this study, a smooth S-duct shape is generated using an automated design algorithm and compared with the basic shape through 3D computational fluid dynamics. The flow distortion index at the AIP was evaluated using an automated evaluation tool that extract flow variables at a specific location using the same method as probe measurement for data consistency with experiments.
전달 물성 모델링 방법에 따른 압축기 전체 유로 수치해석
조낙원(Nakwon Jo),김상조(Sangjo Kim),윤준용(Joonyong Yoon) 한국추진공학회 2023 한국추진공학회 학술대회논문집 Vol.2023 No.5
Air within the compressor collides with blades rotating at high speeds, causing significant local pressure fluctuations. Generally, transport properties of gases such as specific heat, viscosity and thermal conductivity are sensitive to temperature change, and when the temperature changes significantly, they should be treated as temperature-dependent functions. However, temperature-dependent functions are sensitive to local variations in flow field, which can make convergence difficult and increase computational time. In this paper, the effect of modeling methods for transport properties on predicting the internal flow of the compressor is analyzed using 3D computational fluid dynamics tool, ANSYS CFX 2019R1 and confirms the convergence by applying temperature-dependet property models to full flow passage model of a 2 stage compressor.
대형 디젤엔진용 후처리시스템 구조에 따른 유동 특성 연구
조낙원(Nakwon Jo),문성준(Seongjoon Moon),이양로(Yangro Lee),안계원(Gyewon An) 한국자동차공학회 2015 한국자동차공학회 부문종합 학술대회 Vol.2015 No.5
Heavy-duty diesel engine should be mounted with a many string of DOC/DPF to reduce SOF and PM emission. And then, in order to minimize the engine power reduction and DPF recycling decline by mounting such devices, a new catalyst layout need to design that considering the back pressure and heat insulation. In this study, internal flow characteristics of the after-treatment devices by various DOC/DPF structures are computed using STAR-CCM+ v9.04 code. Through this, we propose a new catalyst layout that are numerically compared better pressure resistance and temperature loss of emissions. As a results, a new catalyst layout were predicted by calculating the back pressure more than 4.7% and heat insulation more than 2.06%.