다공튜브의 오리피스 구성에 따른 출구 유동특성에 관한 연구

이상규(Sangkyoo Lee),문남수(Namsoo Moon),이지근(Jeekeun Lee) 대한기계학회 2010 대한기계학회 춘추학술대회 Vol.2010 No.11

The perforated tube, arranging with constant orifices in the circumferential direction of the pipe or duct, was used. The internal flow characteristics of the perforated tube show complex and cross-flow near the exit. The distribution of flow rate at the exit of the perforated tube shows the non-uniform flow, and it is one of the most important parameter in the optimum design of the perforated tube. In addition flow characteristic is affected by the orifice, configuration. The purpose of this study is to find the optimum design parameters which can be control the gradient of mass flow rate distribution at the exit of the orifice. The numerical study was carried out with blociage ratio of the exit plane and Reynolds number of inlet flow.

Urea-SCR 머플러 다공 튜브의 형상 변화에 따른 출구 유동 분포 특성 연구

이상규(Sangkyoo Lee),문남수(Namsoo Moon),이지근(Jeekeun Lee) 대한기계학회 2010 대한기계학회 춘추학술대회 Vol.2010 No.4

Urea-SCR 머플러 다공튜브 형상변화에 따른 유동특성 해석

이상규(Sangkyoo Lee),문남수(Namsoo Moon),이지근(Jeekeun Lee) 한국자동차공학회 2009 한국자동차공학회 학술대회 및 전시회 Vol.2009 No.11

This study reports a numerical analysis of the flow characteristics of the Urea-SCR muffler system with the various geometry of the perforated tube. The perforated tube set inside the muffler is generally used to disperse uniformly the Urea-water solution spray and to increase the reaction inside the SCR catalyst, resulting in the reduction of NOx. The steady flow model was simulated with the general-purpose software package "FLUENT", to study the flow characteristics in the muffler. As the working fluid the air at the room temperature was used, instead of the exhaust gas and Urea-water solution spray mixture. The effects of the hole diameter and the blockage ratio on the flow characteristics were investigated for optimal muffler system design that is attained to produce the uniform velocity or pressure distributions in the front of the SCR catalyst. From the analysis results, it was clarified that the flow characteristics inside the muffler are very sensitive to the perforated tube geometry and significantly affected by the blockage ratio.

폐암환자의 비동일평면 선속 빔 치료 시 HexaPOD evo RT system 의 정확성 평가

장세욱,조강철,이상규,김주호,조정희,Jang, Sewuk,cho, Kangchul,Lee, Sangkyoo,Kim, Jooho,Cho, Jeonghee 대한방사선치료학회 2015 대한방사선치료학회지 Vol.27 No.2

목 적 : 폐암환자의 비동일면 선속 빔(Non-coplanar beam) 을 이용한 방사선치료 시 HeaxPOD evo RT system(6D couch)의 정확성을 평가 하고자 한다. 대상 및 방법 : 본원에서 SBRT 환자 중 비동일면 선속 빔을 사용한 폐암환자 13명과, 동일면 선속 빔을 사용하는 폐암환자 10명을 대상으로 하였다. 대상 환자의 자세보정에 있어 Pitch, Roll, Yaw 방향에 대한 보정을 적용, 미적용으로 구분하고, 레이저(Laser)를 Arccheck(Helical grid diode detectors)의 동 중심점에 정렬시킨 후 Arccheck으로 ${\gamma}$값과 전리함(Pinpoint type chamber)을 이용하여 점 선량을 측정하였다. 평가를 위해 점 선량 측정값과 ${\gamma}$-Index(3% / 3 mm, 2% / 2 mm)를 지표로 비교분석 하였다. 결 과 : HexaPOD 미적용 시 치료계획과 비교하여 동일평면 선속 빔의 경우 ${\gamma}$-Index<1(${\gamma}=1$, 3% / 3 mm) 비율은 97.3%, 점 선량은 0.8% 의 차이를 보였다. 비 동일평면 선속 빔의 경우 각각 90.8%, 0.7%로 나타났다. HexaPOD 적용 시, 같은 조건에서 동일평면 선속 빔의 경우 각각 99.5%, 0.6%를 나타냈으며, 비 동일평면 선속 빔의 경우 각각 97.8%, 0.5%의 결과를 나타냈다. ${\gamma}$-Index<1(2% / 2 mm)의 경우, HexaPOD 미적용 시 동일평면 선속 빔의 경우 82%, 비 동일평면 선속 빔의 경우 78.3%를 나타냈으며 HexaPOD 적용 시 각각 91.2%, 93.4%의 결과가 나타났다. 결 론 : HexaPOD를 적용한 경우가 더욱 정확성이 향상되는 것을 확인할 수 있어, 고 정밀 방사선치료의 비 동일평면 선속 빔 사용 시 HexaPOD 사용이 필요할 것으로 사료된다. Purpose : The aim of this study, evaluate the accuracy of HeaxPOD evo RT system using the non-coplanar beam. Materials and Methods : 13 treatment plans are used which applied non-coplanar beams and 10 treatment plans which coplanar beams are used. the correction value what adjust to 6D couch is determined by each patient's setup errors only rotation direction. The study executed followings. first, Applying the correction value, measure the point dose and calculate the ${\gamma}$-index(${\gamma}=3%$ / 3 mm, ${\gamma}=2%$ / 2 mm). second, acquire data as previous methods without correction by HexaPOD. Results : For comparing the two results, we find out the more precise applying HexaPOD by point dose 0.2% in coplanar and non-coplanar. in the case of ${\gamma}$-index<1(${\gamma}=3%$ / 3 mm), more precise 2.2% in coplanar and 7% in Non-coplanar. Particularly, ${\gamma}$-index<1(2% / 2 mm) show the difference 9.2% in coplanar and 15.1% non-coplanar between apply HexaPOD and dose not apply HexaPOD. Conclusion : Using the HexaPOD is more precise than without HexaPOD. It suggests that HexaPOD evo RT system is very useful for precise and high dose delivery.

직장암 치료시 영상유도 시스템의 유용성 평가

장세욱,안승권,이상규,김주호,이원주,조정희,Jang, Sewuk,Ahn, Seungkwon,Lee, Sangkyoo,Kim, Jooho,Lee, Wonju,Cho, Jeonghee 대한방사선치료학회 2017 대한방사선치료학회지 Vol.29 No.1

purpose: Image Guide System offers therapy precise, especially Intensity Modulated Radiation Therapy. However, organs at pelvis have variation and uncertainties each therapy. it brings IG system for verifying patient's position. In this study, analysis the variation at pelvis during rectal cancer radiation therapy. Moreover design the patient re-setup technique and apply to patients. Material and Method: 40 rectal cancer patient who have radiation therapy. The 530 image which acquired from IG system are analyzed. The bone structure, bladder, gas in the rectum, small bowel, soft tissue, weigh loss are evaluated by the criterion. The criterion are classified by best, good, bad and figure out the ratio with count. The re-setup proceed in case of one or over the two get the bad criterion and figure out the ratio of re-setup results: The ideal of therapy ratio is 19.2 % each criterion. And the good for therapy ratio is 54.9 %, the cases of bad for therapy is 25.8 %. The bad cases are have therapy after re-setup with post process. conclusion: Each pre-treatment image that acquired IG system has different results despite of same patients. The 25.8 % need to re-setup in order to unsuitable therapy. It is implies that the IG system is necessary establishing precise treatment plan like IMRT especially rectal cancer. 목 적: 세기조절방사선치료(Intensity Modulated Radiation Therapy; IMRT)에서 영상유도 시스템은 치료의 정확성 확보에 유리하다. 특히 골반치료의 경우 장기들의 위치와 모양이 환자상태 및 외부적 환경에 따라 변형이 발생하여 치료 전 확인이 필요하다. 따라서 본 연구에서는 직장암 치료 시 골반 내 변화요인을 분석하였고, 자세의 재조정 방법을 고안해 적용하고자 하였다. 대상 및 방법: 본원에서 시행한 직장암 환자 40명을 대상으로 하였고, 환자들의 치료 전 영상 530건을 분석하였다. 평가 항목으로 골격구조, 방광, 직장 내 가스, 소장, 연부조직, 체중감소 여부를 매우 좋음, 좋음, 나쁨 3단계로 구분하였고 각각의 건수와 비율을 산출하였다. 나쁨의 경우가 1개 이상 시 각각의 방법으로 해당 항목에 대해 재조정을 시행하였으며 그 비율을 구하였다. 결 과: 각각의 평가조건에서 치료하기에 매우 좋은 경우는 19.2 %였다. 치료에 적절한 경우는 54.9 %, 치료에 부적절한 경우는 25.8 %였으며, 치료에 부적절한 경우에는 재조정을 시행하여 치료 진행을 하였다. 결 론: 골반 내 장기의 변화는 같은 환자일지라도 치료 시 마다 다른 결과를 나타냈다. 평가 지표에 따라 진행이 부적절한 경우는 25.8 %였으며 재조정을 통하여 환자 자세 재현성을 확보 후 치료가 가능하였다. 따라서 정밀하게 계획되는 IMRT의 직장암 치료 시에는 영상유도시스템을 이용하여 정확한 치료가 필요하다 사료된다.

핵비등 열전달 효과를 고려한 내연기관 냉각수로의 CFD-FE 연성해석 기법

이명훈(Myunghoon Lee),김동광(Dongkwang Kim),이상규(Sangkyoo Lee),임동렬(Dongryul Rhim) 한국자동차공학회 2006 한국 자동차공학회논문집 Vol.14 No.5

핵비등 열전달 효과를 고려한 내연기관의 냉각수 유동 및 복합 열전달 해석

이명훈(Myunghoon Lee),김동광(Dongkwang Kim),이상규(Sangkyoo Lee),임동렬(Dongryul Rhim) 한국자동차공학회 2005 한국자동차공학회 춘 추계 학술대회 논문집 Vol.2005 No.5_1

The present study is to simulate coolant flow in IC engine cooling passages under subcooled nucleate boiling conditions and investigate thermal stress analysis of the solid part. To consider nucleate boiling heat transfer effect, Chen's empirical formula is used through user subroutine programing in CFD code and then nucleate boiling model is compared with Robinson's experimental results, it shows reasonable agreement. This Chen's nucleate boiling model is applied to one cylinder IC engine model and we do cylinder liner thermal stress analysis using temperature distribution data of the cylinder liner.

촉매 삽입형 Urea-SCR 머플러의 내부유동 연구

문남수(Namsoo Moon),이상규(Sangkyoo Lee),이지근(Jeekeun Lee) 한국자동차공학회 2013 한국자동차공학회 지부 학술대회 논문집 Vol.2013 No.5-1

This study reports a numerical analysis of the internal flow characteristics of the integrated urea-SCR muffler system with the various geometries of the multi-perforated tube which is set up between the muffler inlet and in front of SCR catalysts. The multi-perforated tube is generally used to disperse uniformly the urea-water solution spray and to make better use of the SCR catalyst, resulting in the increased NOx reduction and decreased ammonia slip. The effects of the multi-perforated tube orifice area ratios on the velocity distributions in front of the SCR catalyst, which is ultimately quantified as the uniformity index, were investigated for the optimal muffler system design. The steady flow model was applied by using a general-purpose commercial software package. The air at the room temperature was used as a working fluid, instead of the exhaust gas and urea-water solution spray mixture. From the analysis results, it was clarified that the multi-perforated tube geometry sensitively affected to the formation of the bulk swirling motion inside the plenum chamber set in front of the SCR catalyst and to the uniformity index of the velocity distribution produced at the inlet of the catalyst.

다공튜브 오리피스 차단비에 대한 연구

문남수(Namsoo Moon),이상규(Sangkyoo Lee),이지근(Jeekeun Lee) 한국자동차공학회 2013 한국자동차공학회 지부 학술대회 논문집 Vol.2013 No.5-1

A multi-perforated tube indicates the existence of multi holes in various shapes on the surface of long cylinder-type or rectangular tubes. In this study, the flow characteristics of the circular multi-perforated tube with many orifices on the surface were investigated experimentally and numerically. The volume flowrate issuing from each orifice, discharged angle, effective flow area ratio were measured and visualized with the variation of the orifice area ratio at the same blockage ratio. The volume flowrate distributions along the flow direction of the multi-perforated tube tends to be more uniform as larger orifices were positioned at the inlet side of the multi-perforated tube, compared with no orifice area change along the flow direction.

다공튜브 형상변화에 따른 촉매 삽입형 Urea-SCR 머플러 내부유동 해석

문남수(Namsoo Moon),이상규(Sangkyoo Lee),이지근(Jeekeun Lee) 한국마린엔지니어링학회 2013 한국마린엔지니어링학회지 Vol.37 No.5