남한강産주물사에 관한 조사연구

신철수 한국교통대학교 2012 한국교통대학교 논문집 Vol.47 No.-

In Korea, lack of knowledge of chemical composition, permeability, impurities, heat resistance of the sand for moulding sand has prevented the right way of treatment of moulding sand as engineering material. Therefore, we have determined to survey and study on the moulding sand. As the first step, we have started to survey and study on the Nam-Han river sand. The results obtained are as follows; 1. Tte contents of silicate in sand is satisfactorily high and the impurities are little. 2. The hardness is high enough, but compressive strength and permeability are comparatively low. 3. The grain distribution of sand shows that the grain size belongs to the fine and medium sand group. 4. The grain shape of sand is sub-angular. 5. The temper water content in the sand is approximately 6%.

N-S방정식에 대한 수치해법 적용에 대한 연구

申澈洙 忠州大學校 1993 한국교통대학교 논문집 Vol.28 No.-

The finite element method is applied to Navier-stokes equations. A velocity-pressure formultion is used in the analysis. A mixed interpolation is employed for the velocity and pressure. The approach is assessed by comparing the results with preditions of other authors, for various numerical test cases.

90˚흐름 曲管에서의 數値 시뮬레이션

申澈洙 충주대 2000 한국교통대학교 논문집 Vol.35 No.1

In the present study, incompressible, isothermal, developing flow in a 90˚ rectangular cross sectional strongly curved duct with aspect rate 1:1.5 and Reynolds number of 106 has been investigated.In general, flow in a curved duct is characterized by the secondary vortices which are driven mainly by centrifugal force-radial pressure gradient imbalance, and the stress field stabilizing effects near the convex wall and destabilizing effects close to the concave wall.A numerical analysis has been conducted on the interaction of the thermal radiation and natural convection in a rectangular enclosure field with a gray fluid.As the Stark number increases or the optical thickness decreases, the boundary layer thickness and the flow velocity increase.Transition to turbulence is retarded with the increase of the radiation effect.When the optical thickness is one, the Radiation effect is negligible for the Stark numbers larger than 10.

단독주택의 지열시스템 적용 가능성에 대한 연구

신철수,장태익 한국수소및신에너지학회 2012 한국수소 및 신에너지학회논문집 Vol.23 No.5

Due to high oil prices and global warming problems, researching an alternative energy source and decreasing the energy usage will be the key in the future. Unlike other alternative energy sources, geothermal energy is less dependent on the surrounding environment. Geothermal energy is the ideal energy source for buildings due to the simple and space saving installation. The system is semi permanent once it is installed and this will help reduce the energy usage in controlling the climate in buildings. Geothermal energy does not emit carbon dioxide and other gases that are harmful to the environment. Therefore geothermal energy will be the key in solving high oil prices and a decrease in fossil fuels by applying the geothermal energy system to homes to counter future energy crisis.

비등 열전달에 대한 개략적인 최적 핀 설계

신철수 忠州大學校 2009 한국교통대학교 논문집 Vol.44 No.-

For extended surfaces used in boiling liquids, the specified fin-base temperature may be such as to result in simultaneous nucleate, transition, and film boiling at adjacent positions on the fins. If the fins are spines of circular cross section, the optimum shape to minimize the volume of metal resembles a turnip, as shown by Haley and Westwater. The object of the new study was to develop easy-to-machine shapes using cones and cylinders. It was shown mathematically that two cons, base-to-base, give an excellent approximation to the turnip shape. Three such fins were constructed of copper and tested in Freon-113 at atmospheric pressure. The measured, peak heat duties were 5 to 70 percent higher than predicted values, proving that the design method is conservative.

유체 유동 문제의 유한요소법 적용에 관한 연구

申澈洙 忠州大學校 1997 한국교통대학교 논문집 Vol.32 No.1

This study has been accomplished by offering the numerical analysis which is more useful to the parts of simulations of the actual models and time-speed than experimental investigation, for attaining she more detailed informations on flued flow. The finite element method is applied for fluid flow problems. 4 velocity-pressure formulation is used in the analysis. .4 mixed interpolation is employed for the velocity and pressure.

Non-Newtonian Fluids의 유동문제에 전산유체역학의 적용

신철수 忠州大學校 2010 한국교통대학교 논문집 Vol.45 No.-

The purpose of this paper is to apply the numerical simulation techniques the internal flow problems of non-Newtonian fluids. Rheologically different fluids such as water, aqueous Carbopol solutions, aqueous Separan solutions and blood are employed for the numerical approach to understand flow phenomena in the stenotic tubes and the bifurcated tubes. Mathematical formulation of rheological properties for the non-Newtonian fluids are obtained by a function of the shear rate using the modified power law model, the Carreau model, the modified cross model and the modified Powell-Eyring model. the results numerical application to the internal flow problems are as follows: (1) The numerical results for the non-Newtonian fluids in the stenosed tubes and bifurcated tubes are in good agreement with the experiments. (2) The proposed modified power law model is proper to describe the rheological behaviors of the non-Newtonian fluids. (3) Some differences in flow behaviors of Newtonian and non-Newtonian fluids are observed. (4) The pressure loss coefficient in the stenotic tubes can be determined by numerical methods

LiBr-H2O 방식에 의한 흡수식 냉동기의 성능해석에 관한 연구

신철수 忠州大學校 2007 한국교통대학교 논문집 Vol.42 No.-

This paper is a study on the performance characteristics of a lithium bromide water absorption refrigeration system. The equation of the coefficient of performance is derived for a single stage cycle and the value calculated, When the evaporator temperature is at 40 ℉ and the efficiency of the liquid heat exchanger 0.75, under the assumption that the condensate in the condenser and the vapor in the evaporator are saturated. Through the calculated performance curves, the factors which influence the performance characteristics are discussed. It showed the coefficient of performance is affected by the condenser temperature and absorber temperature rather than the generator temperature, and only the water cooling systems are available when flat-plate , collectors are used as the energy source of the lithium bromide water cycle. change of Glucose.

나비에-스토크방식의 해석에 유한해석법의 적용

윤재복,서상호,신철수 崇實大學校 生産技術硏究所 1991 論文集 Vol.21 No.-

Finite analytic method is employed to solve the Navier-Stokes Equations with the velocity-pressure formulation. The Chorin's artificial compressibility method and the method of pressure corrections are employed in order to be able to compute the pressure explicitly. The results are compared with the stream function-vorticity ones, and those of finite element and finite difference methods.

P.V.C.Pipe 內에 있어서의 Non-Newtonian fiuid의 흐름 狀態에 對한 硏究

申澈洙 忠州大學校 1984 한국교통대학교 논문집 Vol.17 No.2

This study is to confirm experimentally the friction factor in the P.V.C. Pipe. Non-Newtonian fluids have many properties that can not be observed in Newtonian fluids. However, as the reynolds number is increased the rougher tube results deviate fron the maxium drag reduction asymtote sooner than the less rough tube results. There appears a systematic deviation fron the maxium drag reduction asymptote depending on the relative roughnes just as friction factor for the Non-Newton-ian fluid in the rough tubes exhibit in the turpulent region.