• 자원환경지질
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• 제27권4호
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• pp.397-409
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• 1994

지각의 두께에 따른 지열류량을 표시한 그림에서 나타나는 산만성은 다른 두개의 구조구를 전제하고 지구 동력학적 과정과 열적 감쇠현상을 적용하면 설명이 분명하게 된다. 높은 지열류량은 지각이 가늘게 확장되어 얇아진 열곡지역뿐만 아니라 트러스트 구조작용으로 지각이 두껍게 되고 지각의 열생산이 많은 조산대 지역의 특징이다. 지질학적 시간이 경과함에 따라서 지각평형작용에 의해 두꺼운 지각은 융기와 침식작용으로 얇게 되며 얇은 지각은 침강과 퇴적작용으로 두껍게 된다. 지열류량은 배경의 맨틀 지열류량과 평형을 이루는 값까지 감소하게 된다.

• Journal of Mechanical Science and Technology
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• 제15권10호
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• pp.1423-1433
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• 2001

A flow modeling method has been developed to analyze the flow in the annular base (rear- facing surface) of a circular engine nacelle flying at subsonic speed but with a supersonic exhaust jet. Real values of exhaust gas properties and temperature at an altitude of 30, 000 feet are employed. Potential flows of the air and gas streams are computed for the flow past a separated wake. Then a viscous jet mixing is superimposed on this inviscid solution. Conserva- tion of mass, momentum and energy for the wake flow field is achieved by multiple iterations with modest computer requirements.

• 설비공학논문집
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• 제8권1호
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• pp.26-36
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• 1996

Many researches were carried out to estimate heat transfer rate on a circular cylinder in a uniform flow. Various empirical correlations were suggested in the past through experimental studies, however there are considerable discrepancies in the estimated values of heat transfer coefficient. The effect of fluid physical properties on the forced convective heat transfer between a circular cylinder and the external flow was numerically investigated in the present study, The flow and temperature fields were solved using a Finite Volume Method over a wider range of Prandtl number(0.7-40,000) than existing correlations. The cold as well as the hot cylinders in the uniform liquid flow of constant temperature were investigated. A unified correlation was obtainde for both cases.

• Advances in environmental research
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• 제5권4호
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• pp.263-282
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• 2016

Contaminant transport in groundwater induces major threat and harmful effect on the environment; hence, the fate of the contaminant migration in groundwater is seeking a lot of attention. In this paper a two dimensional numerical flow and transport model through saturated layered soil is developed. Groundwater flow and solute transport has been simulated numerically using proposed model. The model implements the finite volume time splitting method to discretize the main equations. The performance, accuracy and efficiency of the out coming numerical models have been successfully examined by two test cases. The verification test cases consist of two-dimensional, groundwater flow and solute transport. The final purpose of this paper is to discuss and compare the shape of contaminant plume in homogeneous and heterogeneous media with different soil properties and control of solute transport using a zone for minimizing the potential of groundwater contamination; furthermore, this model leads to select the effective and optimum remedial strategies for cleaning the contaminated aquifers.

• 대한기계학회논문집A
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• 제20권4호
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• pp.1225-1232
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• 1996

In this paper the vibration and power flow analysis for the branched piping system conveying fluid are performed by wave approach. The uniform straight pipe element conveying fluid is formulated using the dynamic stiffness matrix by wave approach. The branched piping system conveying fluid can be easily formulated with considering of simple assumptions of displacements at the junction and continuity conditions of the pipe internal flow. The dynamic stiffness matrix for each uniform straight pipe element can be assembled by using the global assembly technique using in conventional finite element method. The computational method proposed in this paper can easily calculate the forced responses and power flow of the branched piping system conveying fluid regardless of finite element size and modal properties.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2010년도 제34회 춘계학술대회논문집
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• pp.264-267
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• 2010

This research focuses on the development of numerical code to deal with compressible two phase flow around three dimensional objects combined with cavitation model suggested by Weishyy et al. with k-e turbulent model. The cryogenic cavitation is carried out by considering the thermodynamic effect on physical properties of cryogenic fluids in physical point of view and implementing the temperature sensitivity in the energy equation of the government equations in numerical point of view, respectively. The formulation has been extensively validated for both liquid nitrogen and liquid hydrogen by simulating the experiments of Hord on hydrofoils. Then, simulations of cavitating turbopump inducers at their design flow rate are presented. Results over a broad range of Nss numbers extending from single-phase flow conditions through the critical head break down point are discussed. In particular, thermal depression effects arising from cavitation in cryogenic fluids are identified and their impact on the suction performance of the inducer quantified.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.392-401
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• 2006

In the July of 2006, devastating rainfalls ravaged the terrain in the province of Kangwon. These rainfalls resulted in debris flows, landslide and overflow over the habitat. Following these events, the urgent field study and countermeasures were to be needed and several methods were indicated. At each site, field observations were made and the properties of the channel and debris flow were broadly characterized. Debris flows are a natural hazard which looks like a combination of flood, land and rock slide. The same goes for that case, debris flow has been reported frequently overseas and the extent of damages has been increased. But the hazards "debris flow" is still insufficiently researched and futhermore debris flows are very hard to predict. In this paper, the general overview of the debris flow problem and the mitigation method will be presented

• Journal of Communications and Networks
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• 제8권3호
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• pp.313-322
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• 2006

We consider a power controlled code division multiple access (CDMA) system with multiple flow types. At each of the N nodes, there are F flow types with different signal-to-interference-and-noise-ratio (SINR) requirements. To keep the complexity of the transmitter low, we assume that each node uses the same power level for all its flows. The single flow case has been fully solved and is well-understood. We concentrate on the multiple flow case, and use a novel and different approach. For the uplink problem with N = 2 and F arbitrary, the necessary and sufficient conditions to have a solution are found and proved. For the general N > 1 uplink problem, we provide a necessary condition for the problem to have a solution and an iterative algorithm to find the optimum solution. For the downlink case with F > 1 some properties of the optimal sequences are obtained.

• 전기학회논문지
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• 제60권2호
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• pp.338-343
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• 2011

In this paper, the FT-IR, conductivity and flow electrification phenomena of Vegetable oils were discussed. Vegetable oil has high flash point and eco-friendly properties compared to conventional mineral oil. Accelerated aging transformer oil samples produced in the oven at 140[$^{\circ}C$] for 500 hours, 1000 hours, 1500 hours, 2000 hours. Serial device to measure the flow electrification phenomena was designed and fabricated. Pico ammeter and the Labview data measurements were utilized. The effects of Temperature and antistatic agent on fluid flow electrification were investigated. Both Mineral and vegetable oil showed similar trends for temperature change. The polarity reversal occurred in mineral oil with antistatic agent above 10 ~ 30[ppm] and in vegetable oil with antistatic agent above 5[ppm].

• 한국인쇄학회지
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• 제30권2호
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• pp.23-33
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• 2012

With the development of many display technologies currently applied to them in the field of printed electronics, there have been many researches that high resolution printing for thin and uniform pattern. In this paper, printing ink flow properties in the reverse offset mechanism were simulated. The aim of this research is to expect the ink flow behavior between cliches to make fine pattern by a printing technique which is a reverse offset. The simulation results show that almost the same as the experiments and the flow behavior according to the ink film thickness and printing pressure changes could be expected.