In this study, the cooling performance of the motor was analyzed according to the number and the length of the fins of the heat sink, and at the same time, the effect of forced convection on the cooling performance improvement by changing the air flow speed of the cooling fan was conducted. In order to find out the cooling performance in terms of turbulent kinetic energy, pressure, and temperature according to the number of heat sink fins, length of fins, and wind speed of the cooling fan, an aluminum heat sink was modeled according to the size of the motor. The heating value of the motor was calculated, and it was set to be the same under all analysis conditions. The turbulence model applied for numerical analysis in this study used the standard k-ε model. As a result, it was confirmed that the cooling effect of the heat sink increases as the air flow speed of the cooling fan, the number of fins, and the length of fins increase.
The purpose of this study is to analyze the temperature and heat resistance distribution, which is a criterion for evaluating the cooling performance, by using computer simulation of the cooling system combined with the CPU of the individual highest heat generation section, and use it as important data for the heat sink design. Using a single material of Al 6063-T5, which is an integral part of the desktop, fan and heat sink, fins and base, the analysis was carried out with various fin numbers, thicknesses, pitches and shapes of heat sinks. Ambient temperature, 25°C, heat source, 130W and cooling fan speed, 2500 rpm (50CFM) were used as boundary conditions, and heat transfer characteristics regarding temperature distribution and heat resistance were investigated using ANSYS Icepak. As a result, it has been found that as the number of fins of heat sink increases, the heat dissipation area increases to decrease heat resistance, and as the distance between each fin decreases, the ventilation resistance increases to decrease the flow intensity of the cooling air in contact with the heat dissipation area. The sunburst array also exhibits better heat transfer characteristics by obtaining a lower distribution of heat resistance with a cooling effect of about 10°C than the one-way basic array.
Recently, as demand for Electric Car has been increasing, it has been a main factor that maximizing performance and ensuring the stability of the Electric Car battery to increase the reliability of Electric Car. Above all the study on thermal control in a big influence on the performance and battery life is growing in parallel. This study has compared cooling effect of an Electric Car battery between battery with Heat Sink and without Heat Sink for optimum design of Electric Car battery. Battery is simply modeled into four cells, divided into two cases of battery with Heat Sink that attached on the cell's side and without Heat Sink. And this research was conducted on forced convection. The battery which is designed by this way was numerically analyzed by CFX 14.5. Numerical results, revealed that the battery with Heat Sink was superior in terms of cooling effect. According to the numerical analysis by battery cell's temperature variations, the battery with Heat Sink turned out to be superior in cooling effect to the battery without Heat Sink.
In recent years, urban areas occurred several times a sinkhole. In Korea, this limestone area where the sink hole sink holes occur based on not much was seen as a very rare phenomenon. However, the occurrence of accidents in recent Subsidence and urban areas is occurring in the limestone sinkhole may yet see another one called artificial Subsidence phenomenon. Subsidence in urban areas can have various causes, such as depression groundwater level changes due to the influence of soil, underground, etc. underground utilities by anthropogenic actions. But a lot of research on natural sinkhole by geological experts continued steadily since the past Subsidence that occurred in recent years the city has become an urgent problem to formulate a countermeasure to be very concerned about the human and material damage. In this study, the city by analyzing existing research on the causes and countermeasures of Subsidence recently released look at the announced sinkhole, published statistics and cases of Subsidence data, and overseas corresponding practices in each relevant agencies and to suggest measures for local Subsidence.
The heat generated by the internal electro-mechanical device is not transferred to the outside, to degrade the performance of the electronic device, or the cause of failure. Heat sinks are used to control the heat. Thermal performance of the heat sink of the pine type and pin type was analyzed using ANSYS software. The numerical results were compared with the thermal performance of the pine type and pin-type heat sink. The results of the numerical simulation showed that Pine type heat sink showed an approximately 58 percent better heat transfer rate with forced convection than Pin type heat sink.
최근 국내외 많은 지역에서 발생하는 싱크홀은 그 발생의 규모와 시기를 예측하기가 어렵다. 현재의 기 술로는 싱크홀이 발생할 가능성이 있는 위험지역에 Coring을 이용하여 도로하부 공동의 유무를 파악하는 방법이 최선이다. 하지만 포장된 도로에 Coring을 실시하면 그 후 보수하더라도 보수한 부분이 취약해져 추가 파손이 발생하기 쉽다. 따라서 도로하부에 존재 가능한 싱크홀을 찾기 위해 무작위로 Coring을 실시 하는 것은 상당히 비효율적인 방법이다. 이러한 단점을 보완하기 위해 도로포장면의 파손 없이 도로하부 에 싱크홀이나 공동 혹은 이상대의 유무를 파악하기 위해 전기비저항 탐사(Resistivity Survey)방법을 이 용하였다. 하지만 현재 실시되고 있는 전기비저항 탐사는 지면과 접촉하는 전극부가 말뚝형태를 하고 있 어 도로 천공이 불가피하다.
본 연구의 목적은 기존의 전기비저항 탐사의 단점을 보완하여 도로의 파손 없이 하부에 존재하는 싱크 홀 등을 파악하는 것이다. 전기비저항 탐사의 전극부를 기존의 천공방법에서 접지방법으로 변형하여 전기 비저항 탐사를 실시할 수 있음을 파악하고 싱크홀과 지반연화를 모사한 실내실험을 통해 접지전극방식의 전기비저항 탐사기법을 검증한다.
LED industry in the world, is rapidly emerging as an important policy means of each countries for climate change, saving energy and international environmental regulations. And incandescent bulb regulatory policy in each country is the role of growth catalysts for the LED lamp industry, it is expected to increase research and investment for the LED package in the future. However, In spite of the growth of the LED lamp industry, the price of the world LED lamp has been declining more than 30% per year and it is accelerating further. Therefore, an alternative techniques for high performance and cost reduction of the LED lamp has been studied. In this study, we studied the aluminum extrusion product inserted heat sink as a one of the alternative techniques which can improve the thermal efficiency and reducing costs. As a result, radiant heat effect was improved around 44.5% higher than the thermally conductive resin heat sink
This research is to investigate the cooling performance analysis of the heat sinks for LED light with four different fin types and two different fin numbers (16EA and 64EA) of heat sinks. Temperature distributions of fins over the flow domain are numerically calculated for the optimum design of heat sink fin types with uniform initial temperature of the bottom of the fins. According to the calculations of convective heat transfer coefficient between fin and atmosphere in the flow domain, S-curve fin type of heat sinks with 64EA of fins reveals the highest cooling performance of the heat sink fin types in the present cooling heat sink model.