순환유에서의 난류열전달에 대한 연구

이충구 충북대학교 건설기술연구소 1984 建設技術論文集 Vol.3 No.1

Circular tube jet occurs when the motion rates of jet and neighboring flow are high aryl accompanied with recirculating flow, Many studies have been conducted on the circular tube jet(1, 2, 3). Experiments on heat transfer at a wall suface(4) and on flow recognition(5) indicate that maximum point of heat transfer rate was not coincided with the reattachment point of jet if recirculating flow exists. The purpose of this study was to interpretate the mechanism of turbulence heat transfer in recirculating flow, The turbulence flow was measured in recirculating area of circular tube jet using Laser Doppler Anemometer, In additions shear stress at a wall surface was measured to explain how high level of turbulence flow stimulates heat transfer and flow velocity was measured using Laser Dopper anemometer.

韓國字典 成立의 考

이충구 반교어문학회 1991 泮橋語文硏究 Vol.3 No.-

다공질매체내의 유체유동 특성에 관한 연구

이충구,황춘복,Lee, C.G.,Hwang, C.B. 대한설비공학회 1993 설비공학 논문집 Vol.5 No.4

In this research, unsteady groundwater flow in unconfined and homogeneous three layer aquifers is studied theoretically and experimentally. Numerical solutions are obtained by Runge Kutta and Runge Kutta Gill method after transforming the governing nonlinear partial differential equations to nonlinear ordinary differential equations. Experimental apparatus includes a test section filled with fine, medium and coarse sands. Experimental results are compared with the numerical solutions and both experimental and numerical results correspond well with each other. This numerical approach may be also applied to the cases which have more aquifers.

4각 리브로된 표면조도에 의한 유체유동 및 열전달 증진에 관한 연구

이충구,Lee, C.G. 대한설비공학회 1992 설비공학 논문집 Vol.4 No.3

Theoritical Study is performed on heat transfer and fluid flow induced by square-ribbed roughness elements in a concentric annulus. The fluid properties were assumed to be constant, and the radius($r_m$) of the maximum speed point was found by using the principle of equation of Leung and Labib. The Nusselt number and friction factor as a function of the Reynolds number($R_e=10^4$, $5{\times}10^4$, $7{\times}10^4$, $10^5$) in artifical roughness $S/{\epsilon}=5,10,20,30$, $P/{\epsilon}=2,5,8$ and prandtl number = 0.72 have been discussed. In this study, it has been found that the Nusselt number and friction factor of rough wall are larger than those of smooth ones.

說文解字에 나타난 漢字字源 硏究

이충구 한국한자한문교육학회 2006 漢字 漢文敎育 Vol.17 No.-

The purpose of the study is as follows ; Firstly, it reviews the shapes and meanings of the Chinese Characters in the book of Seolmunhaeja. Secondly, it shows to what extent the Korean interpretations or commentaries of the Chinese Characters are correct. Thirdly, it tries to put the proper orientations of the interpretations on the Chinese letters by way of studying the making ways of the basic Chinese Characters. Lastly, it claims that the numbers of the basic Chinese Characters could be reexamined through the ways of increasing or decreasing them. In the introduction, it roughly explains the whole contents of the Book including the general system of the Book and the six ways of making Chinese letters. In the next chapters, it focuses on the relations between the shapes and meanings of letters, especially seeing it that the shapes have influences on the meanings. And it tries to find out what the correct Korean commentaries of the Chinese meanings are. When we examine how they are put into Korean, we shows whether the Korean translations are correct or not. In the part of dealing with the basic Chinese Characters, we should say the fact that the original 540 basic characters in the Book has been decreased to the current 214 and how it was happened. In addition, we divides between the necessary basic characters to be added and the unnecessary ones. In conclusion, this study is to make apparent the ways of interpreting Chinese Characters in the Book, the relations of the shapes and meanings of the letters, and the problem of the Korean commentaries. Above all, it is meaningful that we claims the need for increase or decrease of the basic characters. As a result, the study will contribute the ways of interpreting Chinese Characters and arranging the order of them in the dictionaries. 본고는 說文解字의 字形解說과 그에 의한 字義를 살펴보고 國語 註釋의 適宜性을 따져보고 部首의 경향을 살펴봄으로써, 현금의 漢字 註釋이 나아가야 할 방향을 제시하고 部首의 增損을 통해 그 수효의 재조정을 추구한 것이다. 위의 과제를 달성하기 위한 구체적 작업은 說文解字 槪要, 字形解說과 字義의 相關關係, 字義의 國語 註釋 適宜性 問題, 部首 增損을 다루었다.설문해자 개요에서는 설문의 체제ㆍ내용 그리고 六書의 표현양식 등을 제시함으로써 설문에 대한 기본 인식을 꾀하였다. 字形解說과 字義의 상관관계에서는 자의와 자형해설을 대비함으로써 자의에 자형해설이 적용되는 실례를 들어 살펴보았다. 그리고 자의의 國語 對譯語 제시를 추구하였다. 자의의 국어 주석 적의성 문제에서는 설문의 한자 주석이 국어 주석으로 표현될 때의 경향을 살피고, 그 적의성의 밀착과 불밀착을 지적하였다. 部首 增損에서는 설문 부수 540부수가 현재의 214부수로 변동되었으나, 그것이 계승된 실상을 살피고 증손할 부수를 제시하였다.이 작업은 설문의 한자해설의 경향을 드러냈고, 標題字의 字義와 자형해설의 관계를 밝혔고, 한자의 국어 주석의 정밀성을 꾀하였고, 부수 수효를 증손시키는 논의를 제기한 것이다. 이는 결국 한자의 訓 및 자형 배열 문제에 일조를 하는 것이다.

다공질매체내의 류체류동

이충구,조성환 대한기계학회 1976 大韓機械學會誌 Vol.16 No.1

Groundwater flow in a two-layer aquifer is studied theoretically and experimentally. Nonlinear differential equations are independently linearized for the upper and the lower layer, and approximate solutions are obtained. Fine sands and coarse sands are used in experiments. For steady flow, theoretical solutions agrees excellently with experimental results For unsteady flow, however, agreement is not so good, because the experimental conditions do not match with theoretical assumptions.

폐 바이오매스를 이용한 폐열 회수 열교환기에 관한 연구

이충구,이세균,이계복,이석호,김정현 대한설비공학회 2004 설비공학 논문집 Vol.16 No.6

Waste heat recovery system was studied numerically and experimentally. Heat exchanger system was designed specially to obtain the optimum heat exchanging performance. Brushwood biomass was used for the present experimental study. Two biomass heat recovery systems were designed and developed. Polyethylene helical pipe line of 0.03 m (inner diameter) was installed to recover the heat of biomass dump. The fermentation process of biomass dump was maintained for 12 weeks. The inner average temperature of biomass was about 51 ℃ for both het exchanger systems. The current heat recovery system could recover up to 6 kcal/kg of energy.

多層多孔質媒體內의 流體流動

이충구,서정윤 대한기계학회 1985 대한기계학회논문집 Vol.9 No.5

본 논문에서는 정해를 구하기 어려운 이질의 세개의 층으로 된 비피압대수층 내에서의 물의 비정상유동에 대한 이론 및 실험에 대하여 연구하고자 한다. Unsteady groundwater flow in a three-layer unconfined aquifer has been studied theoretically and experimentally. Two different methods have been used in solving the governing equations of the flow, the nonlinear partial differential equations; (1) The governing equations are linearized for each layer and approximate solutions are obtained. (2) The governing equations are transformed to nonlinear ordinary differential equations, which are solved numerically by Runge-Kutta procedure. Fine, middle sized and coarse sands are used in the experiments. It is found that the solutions from the method(2) ( the reduction of partial differential equations to ordinary differential equations) give better agreement with the experimental results than the solution from the method(1).

[New Year's Greetings] 위기를 글로벌 경쟁력 확보의 기회로 활용해야

이충구 한국자동차공학회 2001 오토저널 Vol.23 No.1

通鑑類의 受容과 通鑑諺解

이충구 반교어문학회 1994 泮橋語文硏究 Vol.5 No.-