• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.41 no.3
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• pp.47-58
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• 2023

This study was conducted through reviewing Aspects of Design and Construction in Entrance Space of the World Heritage Royal Tombs of the Joseon Dynasty, which is equipped with parking lots, ticket offices, toilets, exhibition halls, information boards, and rest facilities for the convenience of visitors and the purpose of this study was to propose a direction for improvement. The results of the study are as follows: First, the reduced area of Royal Tombs of the Joseon Dynasty was unable to fully accommodate the ritual movement line, and as a result, the location of the entrance space in the current royal tomb was decided to accommodate minimal convenience functions. In the meantime, the entrance space of the royal tombs has been relocated or renovated in order to achieve its integrity as a World Heritage Site, rational arrangement of movement lines and spatial utility. Second, the size of the entrance space ranges from 1,000 square meters in Jeongneung in Seoul to 16,000 square meters in Hongyuneung in Namyangju, and the number of annual users varies greatly from 12,000 in Onneung in Yangju to 410,000 in Seonjeongneung in Seoul. Considering the conditions of the 16 royal tombs, the entrance space should be provided at an appropriate scale, reflecting the surrounding land use and accessibility that affect the influx of users, the size of the site, and the king's awareness and preferences. Third, the location of the parking lot, the presence or absence of an outer courtyard and an internal courtyard bordering the ticket and check offices, and the location of the Historical and Cultural Museum made it possible to know the aspects of entrance space of the Joseon Royal Tombs, where the spatial configuration is determined Fourth, according to the royal tombs, it was found that the entrance space should have essential parking, access control, information, and convenience functions, and that support, exhibition, passage, and recess functions should be optional. At this time, the management office and the Historical and Cultural Center are in charge of support and exhibition functions. The function of passage can be a strategy that provides a sense of entry and the function of recess which has been introduced in only four royal tombs requires an appropriate location and landscape access.

• Nuclear Engineering and Technology
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• v.18 no.3
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• pp.209-217
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• 1986

The inlet coolant temperature reduction technique has been used to extend the load follow operation further in the end-of-cycle-life(EOL). In order to simulate the technique and calculate the nuclear characteristics of a PWR core according to the load follow operation, the three dimensional computing system has been established. The analysis was performed in both MINB and SPINR modes of typical 12-3-6-3 locad follow operation for the EOL of KNU-1 plant. Moreover, the capability of return-to-power has been also tested for those two modes with the system analysis by the RETRAN-02 code. The results show that it has no difficulty to extend the load follow operation further in the EOL by applying the inlet coolant temprature reduction, and also the spinning reserve capacity(SRC) increases by 13% in MINB mode and 14% in SPINR mode Bore that used by control rods only, for 14$^{\circ}$ F drop in the inlet temperature.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.4
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• pp.253-260
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• 2013

Ice accretions on the surface around a rotorcraft air intake can deteriorate the safety of rotorcraft due to the engine performance degradation. The computational simulation based on modern CFD methods can be considered extremely valuable in analyzing icing effects before exact but very expensive icing wind tunnel or in-flight tests are conducted. In this study the range and amount of ice on the surface of anti-icing equipment are investigated for heat-on and heat-off modes. It is demonstrated through the computational prediction and the icing wind tunnel test that the maximum mass and height of ice of heat-on mode are reduced about 80% in comparison with those of heat-off mode.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05a
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• pp.603-608
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• 1998

유체내의 물체 주위에서 유동박리로 인해 생성되는 와류쉐딩은 열전달이나 물질전달을 촉진시키는 이점이 있으나, 항력을 증가시키거나 유동 및 온도의 요동에 의해 구조물을 손상시키는 단점이 있다. 특히 물체와 주위 유동 사이에 공진이 일어나면 항력값이 증가하면서 항력과 양력의 진폭이 급격히 증가하여 물체에 심각한 손상을 초래할 수 있다. 본 연구에서는 레이놀즈수 200 이하의 층류유동에서 공진시 물체 주위의 유동현상과 이로 인한 양력과 항력의 변화들을 수치해석방법을 통하여 분석하였다 수치해석은 일반좌표계에서 유한체적법을 적용하여 Navier-Stokes 방정식을 차분화하였다. 이때 방정식의 종속변수로는 공변속도를 채택하였으며, 이산화된 방정식은 분리단계법을 이용하여 수치해를 구하였다. 입구유속의 강제진동에 의한 사각실린더 주위의 와류쉐딩시 공진이 발생하는 강제진동수의 범위는 원통실린더의 경우와 유사하였으나 상대적으로 폭이 더 좁았다 그리고 공진이 발생하는 강제진동수의 범위는 진폭이 증가할수록 증가하였다. 쉐딩 진동수가 일정하면서 입구유속의 진폭이 증가하면 이에 비례하여 실린더 주위의 유속이 상대적으로 증가하게 되어 와도가 강해지면서 입추유속 진폭에 비례하여 항력의 평균값 뿐 아니라 항력과 양력의 진폭도 증가하였다. 그리고 실린더 뒷면의 와류 생성영역은 진폭에 비례하여 감소하였다. 진폭의 변화에 따라 상변화가 서로 상이한 것은 실린더 뒤쪽의 와류들이 상하면의 합력차이를 변화시켰고 이것이 진폭변화에 따라 상변화를 상이하게 나타나게 한 원인으로 진폭이 클수록 실린더 뒤쪽에서 압력변화가 심하게 변하면서 실린더 앞쪽까지 더 많은 영향을 미쳤기 때문이다.선원의 사용자에게 제공되는 최종방사능을 평가하는데 유용하게 사용될 수 있다.r의 분포를 보였다.cting the effect of earthquake on structures. This paper is based on the presented paper at the Bertero Symposium held in January 31an4 February 1 at Berkeley, California, USA which was entitled "Needs to Evaluate Real Seismic Performance of Buildings-Lessons from 1995 Hyogoken-Nambu Earthquake-". The lessons for buildings from the damage due to the Hyogoken-Nambu Earthquake are necessity to develop more rational seismic design codes based upon a performance-based design concept, and to evaluate seismic performance of existing buildings. In my keynote lecture at the Korean Association for Computational Structural Engineering, the history of seismic design and use of structural analysis in Japan, the lessons for buildings from the Hyogoken-Nambu Earthquake, the

• Applied Chemistry for Engineering
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• v.26 no.1
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• pp.67-73
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• 2015

Using a computational fluid dynamics technique, the flow characteristics and particle residence time in a Taylor reactor were studied. Since flow characteristics in a Taylor reactor are dependent on the operating conditions, effects of the inlet flow velocity and reactor rotational speed were investigated. In addition, the particle residence time of $LiNiMnCoO_2$ (NMC), which is a cathode material in lithium-ion battery, is estimated in the Taylor vortex flow (TVF) region. Without considering the complex chemical reaction at the inlet, the effect of Taylor flow was studied. The results show that the particle residence time increases as the rotating speed increased and the flow rate decreased.

• Journal of Biosystems Engineering
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• v.18 no.3
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• pp.275-287
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• 1993

The flow characteristics of the transitional oscillatory flows are investigated analytically and experimentally in the entrance region of a square duct. The systems of conservation equations are analytically solved by linearizing the non-linear convective terms for the developing transitional oscillatory flows in a square duct. The analytical solutions are obtained in the form of infinite series for the velocity profiles. The experimental study for the air flow in a square duct is carried out to measure the velocity profiles and waveforms by using a hot-wire anemometer with the data acquisition and processing systems. The theoretical and experimental results provide the major characteristics of the developing transitional oscillatory flows, such as velocity profiles, velocity waveforms, and entrance length. The velocity profiles in the decelerating phase are larger than those in the accelerating phase for the developing transitional oscillatory flows. The correlations of the entrance length of the transitional oscillatory flows in a square duct are found to be $Le/Dh=K{\cdot}Re_{os}/2({\omega}^+)^2$, where K is 1.23 of an experimental constant.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.973-976
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• 2011

In this paper, the conjugated heat transfer anslysis was performed about an electric heater used in a combustion test equipment of a combustor engine to figure out a physical phenomenon that heater coil was periodically cut during heating test. The result of analysis is that the temperature of coil at coil inlet region was increased locally because the velocity of air was slow in that region. The coil of heater was moved to 25mm downstream so that the structure stability of coil was assured by the decrease of the coil temperature due to increase of an air velocity.

• Journal of Advanced Marine Engineering and Technology
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• v.20 no.5
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• pp.58-67
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• 1996

In the present study, the pressure distribution, wall shear stress distribution and friction factor of developing turbulent pulsating flows are investigated theoretically and experimentally in the entrance region of a square duct. The pressure distribution for turbulent pulsating flows are in good agreement with the theoretical values. The time-averaged pressure gradients of the turbulent pulsating flows show the same tendency as those of turbulent steady flows as the time-averged Reynolds number $(Re_{ta})$ increase. Mean shear stresses in the turbulent pulsating flow increase more in the inlet flow region than in the fully developed flow region and approach to almost constant value in the fully developed flow region. In the turbulent pulsating flow, the friction factor of the quasi-steady state flow $({\lambda}_{q, tu})$ follow friction factor's law in turbulent steady flow. The entrance length of the turbulent pulsating flow is not influenced by the time-averaged Reynolds number $(Re_{ta})$ and it is about 40 times as large as the hydraulic diameter.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.6
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• pp.511-520
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• 2007

WAM(WAve Model), deep water wave model has been extended to the region of shallow water, incorporating wave breaking, and triad wave interaction. To verify the model, numerical simulation of waves in Youngil bay, Pohang is performed and the simulated results show good agreements with measured wave data sets, one station at the mouth of bay and two stations inside the bay. As waves propagate toward the shore, wave height gradually diminishes by bottom friction and wave breaking, and wave direction, initially NE changes normal to the shore due to depth refraction.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.6
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• pp.38-45
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• 2016

A study was conducted on the effect of leading edge location for the performance characteristics of a centrifugal compressor impeller. Five impellers with different leading edge location were selected for numerical analysis. The impeller with leading edge located 10% away from the inlet about meridional distance from entrance to exit showed the best total pressure ratio and efficiency. Also, this case showed relatively uniform flow distribution because of a weak intensity of the separation region at impeller exit. The impeller with leading edge located far from this location showed lowest total pressure ratio and efficiency. Performance of compressor also decreased due to non-uniform flow distribution at impeller exit.