直流電源供應器是將交流電轉換為直流電（AC TO DC Power Supply )，為一般電腦設備不可或缺的電能，又電路結構的不同又可分為有線性（LPS）、交換式（SPS）等兩種。其中交換式電源供應器產品較為輕薄短小及輸出穩定，因此業界電腦設備多屬於使用此設計，本文以450W-12V 輸出規格的1U伺服器專用交換式電源供應器（Server SPS）的散熱研究與分析為對象。
主要是以FLOTHERM 這套CFD套裝軟體做數值模擬方面的分析，並且建立數值模型進行模擬分析，並將模擬結果與實測結果做比對，以確定模型的準確性，再進一步分析模型流場與溫度場，並且針對其散熱設計需改善之處做研究分析。
改善電源供應器的散熱系統同時兼顧成本與可行性前提下，在其有限空間中對散熱片的幾何形狀、最佳風流路徑..等等，做一系列的探討。經過模擬改善整合結果，BD1與Q1晶體溫度明顯下降改善，BD1溫度比原始模型溫度下降11.4 ℃，Q1溫度比原始模型溫度下降3.6 ℃，對於整個電源供應器的穩定性與可靠度大大的提升。

The electric power is the essentials of computer. The main function of AC to DC power supply is to transform alternating current into direct current and provide power for the electrical device. The power supply units are classified as Linear Power Supply (LPS) and Switching Power Supply (SPS) according to the types of circuit structure.
Among these two categories, the SPS is more popular than LPS due to its slight size, high efficiency and stable output. Thus, most of electrical equipments are chosen SPS. The requirements of power supply for 1U server are high power density and limited space. The advantages of SPS are in keeping with the requirements. This is the reason that 1U server SPS is chosen in the investigation.
In this paper, Flotherm software is a numerical analysis tool to create the simulation model for analysis and comparison the simulation result with realistic measurement data, to verify the accurate simulation model for further study of air flow route and temperature distribution.
Based on the strategies of feasibility, low-cost design and cooling-technique improvement, two characteristics (a series of heat sink geometry and the optimization of air flow path) are investigated in the limited space. The result indicates that the temperature values for BD1 and Q1 are decreased 11.4 oC and 3.6 oC, respectively. Thus, the stability and reliability of PSU can be obviously improved.

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