가스터빈 동익 블레이드 회전이 팁 주변 열전달 계수에 미치는 영향에 대한 수치해석적 연구

박근성,임병우,정진영,김우준,곽재수,정진택 한국유체기계학회 2024 한국유체기계학회 논문집 Vol.27 No.1

In this study, the variations in heat transfer coefficients (HTC) on the turbine blade tip were compared for a stationary cascade configuration, a stationary cascade configuration with a moving shroud, and a 3D annular rotating blade with stationary nozzle. The tip HTC distributions of the stationary cascade cases and 3D rotor blade case were numerically investigated. It was revealed that the location and size of the hotspot HTC regions were different for each case. Furthermore, the HTC distributions of the 3D rotor blade were conducted for various relative motions. The results showed that at the lower relative motions, the HTC distribution is similar to that of the stationary cascade configuration. However, as the relative motion is increased, the hotspot location on the tip is moved toward the pressure side and trailing edge of the blade. It was observed that the dominant effect on the HTC pattern around the 3D rotor blade tip is the viscous force generated by the relative motion of the shroud and blade tip, which surpasses the effects of centrifugal and Coriolis forces on the heat transfer characteristics of the blade tip. Additionally, the HTC distributions around the tip of the 3D rotor blade and the cascade configuration with a moving shroud were compared, which showed a similar overall HTC pattern. The findings of this study are anticipated to serve as valuable reference data for the implementation of cooling hole installations based on the hotspot regions on the gas turbine blade tips.

국내 화학물질 관리에 대한 현행 법률 분석과 발전방향

박근성,김현섭,전병한 대한환경공학회 2017 대한환경공학회지 Vol.39 No.11

As the amount of chemicals increases, there is a global movement to reorganize the chemical management system. Korea has also reorganized its chemical management system to enact the act on Chemical Control and Registration and Evaluation etc. of chemical substance. However, it is true that there are not enough explanations in domestic workplaces. Therefore, deepening understanding of chemical control act and searched for a complementary point and future development direction. Through the proposed method, chemical control act should be widely adopted and studied both inside and outside the country as a safe chemical management system. 화학물질의 취급량 증가에 따라 화학물질 관리 제도를 전면적으로 개편하는 움직임이 국제적으로 일어나고 있다. 한국 역시 화학물질 관리 제도를 전면 개편하여 화학물질관리법과 화학물질 등록 및 평가에 관한 법률이 제정되었다. 하지만화학물질관리법의 경우, 법 시행 4년째를 앞두고 여러 개선사항이 드러나고 있다. 따라서 본고에서는 화학물질관리법의 제언한 개선사항에 대한 보완점을 연구하고 그에 맞는 발전방향을 제시하여 화학물질관리법이 오랫동안 안전한 화학물질 관리제도로서 대내외에 널리 도입되고 연구되었으면 하는 바람이다.

누낭비강연결술의 수술성적

박근성 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.2

To determine the success rate and causes of failure of external dacryocystorhinostomy (DCR) in patient with epiphora. Thirty five eyes in 29 patients underwent DCR varying from 14 to 72 years of age were analyzed for this study retrospectively. Minimun follow up time was 6 months. The causes of epiphora were trauma(5 cases), dacryocystitis(1 case) and unknown(24 cases). Obstruction sites were related to anatomical surgical results. Obstruction at the lower lacrimal sac level group of patients showed success rate of 85.0% and 66.7% in canaliculi and common canaliculi level group of patients. The overall anatomical success rate of the procedure was 77.1%, and functional success rate was 60.0%. The causes of failure were granulation tissue and scar formation around the nasal opening in canaliculi and common canaliculi obstruction group especially.

근시안에서 엑시머레이저 굴절교정각막절제술의 효과

박근성,심완섭 충남대학교 의과대학 지역사회의학연구소 1997 충남의대잡지 Vol.24 No.2

The excimer laser allows the controlled ablation of corneal tissue to correct refractive error. we analyzed clinical results of excimer laser photorefractive keratectomy on 70 eyes followed up more than 6 months from May 1994 to December 1996. The patients were divided into 3 groups according to their myopic degree ; group I : -2.0 ~ -3.75D, Ⅱ : -4.0~ -5.75D, Ⅲ : -6.0D ~ -9.0D We evaluated the amount of myopic correction, visual acuity, corneal opacity and complications. At 6 months after operation, uncorrected visual acuity over 0.8 was achieved in 93.7% in group I, 89.6% and 84% in group Ⅱ,Ⅲ. Achieved correction within ±1.0D at six months were 100%, 79.3% and 72% in each group. Mean manifest refraction(spherical equivalent) of each group were -0.34DM -0.4D and -0.85D at six months. Corneal haze was detected at 2 weeks after operation and disappeared at 3 months in almost cases. There was no significant change of intraocular pressure except two cases and delayed epithelial wound healing was noted in only one case. Blurred vision at night was common complain. Photorefractive keratectomy with 193 nm excimer laser appears to be very effective method for reducing low to moderate and range of -6.0D ~ -9.0D of myopia.

태양의 한 조각을 드리는 기업 주식회사 강남

박근성 한국태양에너지학회 2006 태양에너지 : 한국태양에너지학회지 Vol.5 No.3

노안수술후 각막형태검사 변화

박근성,고길환,김용선,이재림,민병무,최시환 충남대학교 의학연구소 2001 충남의대잡지 Vol.28 No.2

We prospectively analyzed the corneal topography of 26 eyes in 26 patients who had undergone scleral expansion for correcting presbyopia. We examined 26 eyes of 26 patients which were devided into 2 groups (mean age: 51 years, range 40-60 years) according to type of scleral expansion band, with computerized corneal topographic analysis system. Preoperatively and 5 times postoperatively (1day, 1week, 2weeks, 1month, 2months), quantitative descriptors of corneal topograpgy such as Sim K (simulated keratometry value), SRI(surface regularity index), and SAI(surface asymmetry index) were measured at each visit. The mean follow-up period was 43 days. Sim K of the operative eyes ranged from 0 to 2.5 (mean, 0.93) before operation, and mean 2.24 at postoperative 1 day in group Ⅰ. In group Ⅱ, Sim K was mean 2.20 at postoperative 1 day and decreased thereafter. SRI was from 0.54 to 1.39 and SAI was from 0.09 to 0.45 before operation. After operation, mean SAI was maximum at postoperative 2 week and mean SRI was maximum at postoperative 1 day and decreased thereafter. After two months, it became minimum. This study demonstrates that quantitative topographic change after scleral expansion for correcting presbyopia were great during first 1 week after surgery but this change diminished thereafter. Further long studies are in progress to evaluate the long term effects of this procedure.

다공성 폴리에틸렌(Medpor^�)을 이용한 안와골절수술의 효과

박근성,이승재 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.2

The objective of this study was to assess the effect of implantation of PPSI(porous polyethylene sheets implant, Medpor^ⓡ) to repair of blowout fracture and the surgical outcome. The authors performed 20 orbital reconstruction using Medpor^ⓡ to reconstruct orbital wall defects through the transconjunctival approach. In 16 cases, silastic sheets also were used. Preoperatively, severe extraocular muscle movement limitation were noted in 13 cases and moderate in 7 cases. Postoperatively 15 cases were full corrected, 3 cases were partially corrected and 2 cases were not corrected. Enophthalmos resolved in 10 of 11 cases. There were significant improvement of symptoms and signs in patients on whom operated within 2 weeks after trauma. There was no infection, implant migration, or exposure. It was concluded that Medpor^ⓡ implant has several advantage of highly biocompatible, easy to handle, contour and position.

풍력발전단지의 후류손실 및 터빈 재배치에 관한 연구

박근성,유기완,김현구,Park, Kun-Sung,Ryu, Ki-Wahn,Kim, Hyun-Goo 한국태양에너지학회 2015 한국태양에너지학회 논문집 Vol.35 No.3

The main objective of this study is to predict the wind power generation at the wind farm using various wake models. Modeling of wind farm is a prerequisite for prediction of annual energy production at the wind farm. In this study, we modeled 20 MW class Seongsan wind farm which has 10 wind turbines located at the eastern part of Jeju Island. WindSim based on the computational fluid dynamics was adopted for the estimation of power generation. The power curve and thrust coefficient with meteorology file were prepared for wind farm modelling. The meteorology file was produced based on the measured data of the Korea Wind Atlas provided by Korea Institute of Energy Research. Three types of wake models such as Jensen, Larsen, and Ishihara et al. wake models were applied to investigate the wake effects. From the result, Jensen and Ishihara wake models show nearly the same value of power generation whereas the Larsen wake model shows the largest value. New positions of wind turbines are proposed to reduce the wake loss, and to increase the annual energy production of the wind farm.

Mitomycin-C 적용시간에 따른 누낭비강연결술의 수술결과

박근성,임진호,민병무,최시환,김창식,김용백 충남대학교 의학연구소 2001 충남의대잡지 Vol.28 No.2

To determine the usefulness of application of Mitomycin-C (MMC) and effectiveness of different concentration of MMC in external DCR. A total of 100 eyes of 87 patients diagnosed with primary acquired nasolacrimal duct obstruction were assigned randomly to either a MMC group or control group. The surgical procedures in both groups were same. In MMC group, a piece of neurosurgical cottonoid soaked with 0.4 mg/ml MMC was applied to the osteotomy site and then was removed after 5 and 10 minutes differently. Nasoendoscopic examination was performed at 1 month, 3 months, and 6 months after surgery for all patients. The causes of epiphora as trauma (20 cases), failed DCR (1 case), sinus surgery (2 cases), unknown (77 cases). The overall anatomical success rate of the procedure was 88% and functional success rate was 79%. Obstruction site was related to anatomical surgical results. Anatomical surgical outcome at lower lacrimal sac level group of patients showed a statistically significant success rate, but functional surgical outcome showed no significant difference between the two groups. The anatomical success rate was 87.7% and the functional success rate was 84.2% in MMC group. The anatomical success rate was 88.3% and the functional success rate was 74.4% in control group. Application of MMC and it's application time were not related to surgical results.

URANS 해석을 통한 천음속 축류팬 정익의 스태킹 라인이 스톨 마진에 미치는 영향에 관한 연구

박근성(Kun Sung Park),자미리 알리(Ali Zamiri),최민석(Minsuk Choi),이병주(Byung Ju Lee),정진택(Jin Taek Chung) 한국유체기계학회 2023 유체기계 연구개발 발표회 논문집 Vol.2023 No.7