• 항공우주시스템공학회지
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• 제9권4호
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• pp.67-72
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• 2015

The analysis has been performed on the blockage effect at the propellant flow passage in a liquid rocket engine. This simulates an example of emergency situation where flow passage is partially blocked. The analysis method has been validated by predicting the pump head and flow rate within 1% precision against the measured data of turbopump-gas generator coupled test. When the oxidizer passage is reduced it is predicted that the mixture ratio decreases, the oxidizer pump head increases and the gas generator pressure increases. When the fuel passage is reduced it is predicted that the mixture ratio increases, fuel flow rate decreases and the fuel pump head increases.

• 한국전산유체공학회지
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• 제8권3호
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• pp.56-65
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• 2003

A numerical procedure for analyzing the heat transfer in a regenerative cooling passage of liquid rocket has been developed. The thermal analysis is based on the numerical model of Naraghi〔1〕. The thermodynamic and transport properties of the combustion gases are evaluated using the chemical equilibrium composition. The pressure and heat flux obtained by the isentropic relation are in good agreement with the result of Navier-Stokes equations. The effect of design parameters on heat transfer is addressed for the pressure loss and temperature variation. Also, their constraints in designing the cooling passage are recommended. Finally, in a heated rectangular duct, the effects of secondary flow on heat transfer are scrutinized by the nonlinear k- e -fu of Park et at.〔2〕.

• Asian-Australasian Journal of Animal Sciences
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• 제4권2호
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• pp.137-141
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• 1991

Rumen liquor characteristics and disappearance rate of dry matter were studied in Kedah-Kelantan cattle and swamp buffaloes fed grass of rice straw-based diet. Cobalt-EDTA and chromium mordented fibres prepared from the faecal material were used to determine the liquid and solid particles movement in both animal species fed with rice straw. Swamp buffaloes showed a more intense rumen fermentation activity than Kedah-Kelantan cattle when both species were fed straw-based diet. The buffaloes also demonstrated faster rates of grass and straw degradation in situ. The fluid outflow rate from the rumen of buffalo ($1.06{\pm}0.19l/h$) was observed to be slower than that of cattle ($1.55{\pm}0.01l/h$). No significant differences between cattle and buffaloes were observed in rumen fluid volume and passage rate of small particles from the rumen.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.291.2-292
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• 2003

The purpose of this study was to investigate the transport characteristics of passage cultured l1uman nasal epithelial cell monolayers grown on Transwell@ inserts using liquid-covered culture (LCC) method. The monolayer of passage 2 and 3 exhibited tight barrier (TEER>1,000 ohmxcm$^2$) in 2-3 days after seeding. In the morphological studies by actin staining and SEM/TEM, the existence of tight junction was clearly observed. (omitted)

• Bulletin of the Korean Chemical Society
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• 제19권10호
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• pp.1068-1072
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• 1998

We present results of molecular dynamic (MD) simulations for the segmental motion of liquid n-butane as the base case for a consistent study for conformational transition from one rotational isomeric state to another in long chains of liquid n-alkanes. The behavior of the hazard plots for n-butane obtained from our MD simulations are compared with that for n-butane of Brownian dynamics study. The MD results for the conformational transition of n-butane by a Poisson process form the total first passage times are different from those from the separate t-g and g-t first passage times. This poor agreement is probably due to the failure of the detailed balance between the fractions of trans and gauche. The enhancement of the transitions t-g and g-t at short time regions are also discussed.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1506-1511
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• 2003

The present study proposes a new structure for a flat plate heat pipe which could embody a thin thickness, any shapes and high heat density a unit area. It is on the structure for the formation of vapor passages and the support of the case of the flat plate heat pipe. A screen mesh is used as the one. To verify the validity of the one, the flat plate heat pipe of 1.08mm thickness was made with a layer of the screen mesh with 14 and 100 mesh number respectively and tested. Here the screen mesh with 14 mesh number plays a role of the vapor passage and the support of the case and the screen mesh with 100 mesh number functions as the wick structure. T he results show that the screen mesh excellently carries out the function of the vapor passage and the support of the case.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집B
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• pp.36-41
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• 2001

In order to simulate wake of stator and a gas turbine engine's balde row, acryl cylinder and a linear turbine cascade were used respectively in this study. Experimental of heat transfer distributions was done on the passage endwall and blade suction surface. Temperature distributions on the experimental regions were obtained through image processing system by using the cholesteric type liquid crystal which has chain structure of metyl$(CH_3)$. To represent the degree of heat transfer, dimensionless St number was used. The results show that heat transfer on the blade suction surface was increased due to the wake from the cylinder and was decreased as the distance between cylinder row and blade row increases. Because of groth of passage vortex, heat transfer distributions on the trailing edge area showed triangular shape which was little changed with wake. On the other hand, heat transfer on the passage endwall was decreased due to the wake from cylinder. As the distance between cylinder row and blade row increases, heat transfer was more decreased.

• 한국응용곤충학회지
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• 제47권2호
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• pp.169-174
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• 2008

눈꽃동충하초균(Paecilomyces tenuipes)의 균사 및 포자 형성에 영향을 미치는 계대증식에서의 특성을 알아보기 위하여, 액체배지로써는 누에 유충분말이 함유된 SL배지와 일반적인 PD배지를 이용하였고, 고체배지로는 누에 번데기 분말을 넣은 현미배지상에서, 세대증식이 이루어진 각 균주에 대해서 조사하였다. 그 결과, 액체 배지에서의 포자 생산량은 세대에 따라 큰 차이를 보였으나, 현미배지에서의 포자 생성율은 세대간에 큰 차이를 보이지 않음으로써, 액체배지에서 계대증식이 고체배지에서의 포자생산량에는 큰 영향을 미치지 않는 것으로 나타났다. 또한 현미배지에 대한 최적 포자 접종량은 각각 $1{\times}10^{10}$ conidia/ml, $1{\times}10^6$ conidia/ml, $1{\times}10^6$ conidia/ml의 농도로 접종하였을 경우 농도에 따른 생산량에 차이가 나타나지 않아서 $1{\times}10^6$ conidia/ml만으로도 충분한 것으로 나타났다.

• 대한기계학회논문집
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• 제19권9호
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• pp.2386-2398
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• 1995

The paper describes the results of an experimental investigation of the heat transfer rate on the endwall surface within the plane turbine cascade passage and includes the effect of the heat transfer for the two different boundary layer thicknesses and Reynolds numbers. The limiting streamlines on the endwall surface have been visualized by the oil film method in order to compare with the endwall heat transfer. The hue-capturing method using the termochromatic liquid crystals with great spatial resolution has been used to provide the local distribution of the endwall heat transfer coefficients. Because the detailed contours of the local heat transfer coefficients over the entire endwall can be obtained from the hue-capturing method, it has been possible to obtain information on the endwall heat transfer within the plane turbine cascade passage from these heat transfer contours.

• 한국항공우주학회지
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• 제31권4호
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• pp.76-81
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• 2003

Kerosene/LOX를 추진제로 사용하는 액체로켓의 추력실에서 발생하는 열유속을 측정하기 위하여 calorimetric combustion chamber를 제작하여 연소실험을 수행하였다. 본 실험에 사용된 calorimetric combustion chamber는 연소실 및 노즐 부분이 각각 하나의 구역으로 제작되었으며, 각각의 구역에서 발생하는 열유속을 측정하기 위하여 냉각제의 출구에 열전대를 설치하였다. 실험은 O/F ratio 2.0에서 연소압 100psi에서 300psi까지 수행하였다. 본 실험에서 연소실에서 복사 열전달은 고려하지 않았다. 측정된 열유속은 연소압에 다라 거의 선형적인 변화를 보였다.