2개의 분리판 사이에서 분사되는 평행 3중 분류에 의한 비정상 난류 유동장 해석

유근종,최훈기,정지훈 國立 昌原大學校 產業技術硏究院 2004 産技硏論文集 Vol.18 No.-

LES is applied to analyze unsteady turbulent triple-jet water flows which are commonly found in thermal stripping phenomena. Current analyses performed to find effect of different SGS models on flow field with partition plates. LES tends to predict higher level of RMS temperatures compared to those of experiment indicating very active mixing effect among triple jets. The LES is found to be able to provide reliable frequency information of temperature fluctuation. The different SGS models show no significant difference in prediction ability, while Smagorinky-Lilly model yields slightly stronger mixing activity.

압력구배기법의 난류유동장 해석에의 적용성에 관한 연구

유근종 國立 昌原大學校 産業技術硏究所 1998 産技硏論文集 Vol.12 No.-

Applicability of the pressure gradient method which is formulated based on pressure gradient is verified against turbulent flow analysis. In the pressure gradient method, pressure gradient instead of pressure itself is obtained using continuity constraint. Since correct pressure gradient is found only when mass conservation is satisfied, pressure gradient method can reflect physics of flow field properly. The pressure gradient method is formulated with semi-staggered grid system which locates each primitive variables on the same grid point but evaluates pressure gradient in-between. This grid system ensures easy programming and reflection of correct physics in analysis. For verifying applicability of this method, the pressure gradient method is applied to turbulent flow analysis with low Reynolds number k-ω model and algebraic stress model. Turbulent flows include fully developed channel flow, backward-facing step flow, conical diffuser flow, and three dimensional annular diffuser flow. Prediction results show that the pressure gradient method can be applied to turbulent flow analysis. However, the pressure gradient method requires somewhat ling computation time. Proper way to find optimum under-relaxation factor, γ , is also need to be developed.

벽면을 통한 유동이 있는 관에서의 난류유동 ( Computation of Turbulent Pipe Flow with Wall Transpiration )

유근종 대한기계학회 1994 대한기계학회 춘추학술대회 Vol.- No.-

벽면을 통한 유체주입이 있는 관에서의 난류유동장 해석 ( Computation of Turbulent Pile Flow with Uniform Wall Injection )

유근종 대한기계학회 1993 대한기계학회 춘추학술대회 Vol.- No.-

압력구배기법의 난류유동장 해석에의 적용성에 관한 연구

유근종 창원대학교 공작기계기술연구센터 1999 연구업적집 Vol.1 No.1

Applicability of the pressure gradient method which is formulated based on pressure gradient is verified against turbulent flow analysis In the pressure gradient method, pressure gradient instead of pressure itself is obtained using continuity constraint. Since correct pressure gradient is found only when mass conservation is satisfied, pressure gradient method can reflect physics flow field properly. The pressure gradient method is formulated with semi-staggered grid system which locates each primitive variables on the same grid point but evaluates pressure gradient in-between. This grid system ensures easy programming and reflection of correct physics in analysis. For verifying applicability of this method, the pressure gradient method is applied to turbulent flow analysis with low Reynolds number k-εmodel and algebraic stress model Turbulent flow, and three dimensional annular diffuser flow. prediction results show that the pressure gradient method can be applied to turbulent flow analysis. However the pressure gradient method requires somewhat long computation time proper way to find optimum under-relaxation factor, γ, is also need to be developed.

운동량변화가 온도변화가 있는 비정상 난류유동장에 미치는 영향

유근종,전원대,김수태 창원대학교 산업기술연구소 2001 産技硏論文集 Vol.15 No.-

In analysis of unsteady turbulent flows with temperature variation, 3 different turbulence models of k-e model, modified k-e model, and Full Reynolds Stress(FRS) model, are applied. 3 Test Cases are selected for verification. These are vertical jet flows with water and sodium, and parallel jet flow with sodium. For overall verification of turbulence models, test cases are analyzed with 2-D and 3-D assumptions. Analysis yields the conclusion that 3-D computation with FRS betters others. However, modified modeling for near wall effect is required to improve its heat transfer characteristic analysis.

LES를 이용한 비정상 난류유동장 연구

유근종,한진우,김수태 창원대학교 산업기술연구소 2001 産技硏論文集 Vol.15 No.-

LES is applied to analyze transient turbulent flows which may cause thermal stripping. The LES is formulated based on Sub-Grid k model. For evaluating performance of the LES, two test cases of vertical water jet flow and parallel sodium jet flow are selected. Through the analysis, the LES confirms that it has proper ability to predict time dependent flow variables such as magnitude of temperature fluctuation and its frequency. For the better prediction, however, the LES is required to be improved through further evaluation of various SGS models and implementation of temperature SGS model into its energy equation.

밀도 변화를 수반한 급작팽창관 내의 난류 회전 유동 분석

유근종 國立 昌原大學校 産業技術硏究所 1997 産技硏論文集 Vol.11 No.-

Low Reynolds number scalar modeling is applied to rotating flow in sudden-expansion pipe. The adopted model is formed by considering near wall behavior of fluctuating velocities and scalar quantities. Analysis results show the improvement of scalar prediction near the wall. The proposed model seems to be adequate to consider wall proximity effects of scalar field. The proposed model is also adequate to predict rotational effects such as destabilization due to additional mean strain effects in entrance region and stabilization due to centrifugal force downstream. Prediction shows general agreement with experimental data, however, circumferential velocity and level of turbulence intensities are somewhat low compared to experimental data. Considering these discrepancy, detailed study is required for further improvement.

Starch - g - Polycaprolactone Copolymer 의 합성과 물성연구

유근종,김경종,이대수 한국공업화학회 2001 한국공업화학회 연구논문 초록집 Vol.2001 No.1

N/A

전력지원체계 연구개발(R&D) 혁신방향 연구

유근종,최병욱 한국방위산업학회 2023 韓國防衛産業學會誌 Vol.30 No.2

이 논문의 목적은 현 국방 국방 연구개발(R&D)이 “국방획득체계 중 일부인 무기체계 위주로 추진되고 있고 전력지원체계분야에는 투자가 저조하여 적극적으로 추진할 수 있는 혁신방향을 고찰하는 데 있다. 미래 국방환경은 민간기술이 국방분야에 신속히 적용되고 특히 AI, Big Data 등 4차 산업혁명 기술은 무기체계 뿐만 아니라 전력지원체계에도 활용이 요구되고있는 상황이다. 그간 방위사업청은 국방 R&D 역량 강화를 위해 4차 산업혁명과 관련된 민간 우수기술을 국방 분야에 적극활용하고 우수 중소・벤처기업의 방산분야 진입 활성화 및 지원을 확대하였으나 이는 무기체계 위주로 이루어졌고 전력지원체계에 대한 활용은 확대가 더욱 필요한 상황이다. 따라서 본 논문에서는 국방 R&D 중 전력지원체계 R&D 현황을 개관하고선행연구를 토대로 R&D 연구분석 모형을 고찰하여 혁신방향을 제시하였다. 연구 결과로 실질적인 거버넌스 정비, 사업 수행및 절차 강화, 예산편성 및 인적자원 확대를 제시하고 장기적으로 국방 연구개발(R&D)의 통합이 필요함을 정책적 제언으로제시하였다. The purpose of this paper is to examine the innovation directions of current national defense R&D, which is focused on weapons systems, and there is little R&D in the field of force support systems, so it is necessary to actively promote innovative directions. In the future defense environment, civil technologies will be rapidly incorporated into the defense sector, and in particular, the 4th industrial revolution technologies such as AI, Big data are required to be used not only in weapon systems but also in power support systems. In the meantime, the Defense Acquisition Program Administration has actively utilized civilian superior technologies related to the 4th Industrial Revolution in the defense sector and expanded the entry and support of excellent small and medium-sized venture companies into the defense sector in order to strengthen the capacity of defense R&D. However, this has been done with a weapon system and the utilization of the power support system is more necessary. Therefore, in this paper, we have outlined the force support systems R&D in Korea defense R&D, have examined the R&D research analysis model based on the previous research and suggested the innovation directions of force support systems R&D. As a result of this study, it was considered that is to establish practical governance, strengthen the R&D performance and procedures, expand the budgeting and human resources. In the long run,, the integration of distributed defense R&D was suggested as a policy proposal.