本實驗在固定鰭片正向面積條件下，設計九種不同幾何尺寸及型式之散熱鰭片，包括：垂直平板、直線鰭片、斷續型鰭片、漸長斷續型鰭片。改變直線鰭片的鰭片間距、鰭片高度，及斷續型鰭片的鰭片長度，以實驗方法探討鰭片垂直放置時的自然對流熱傳性能，及各參數對熱傳性能的影響。 垂直平板平均熱傳係數最高，但因散熱面積較小，所以總熱傳量最低。鰭片間距為影響直線鰭片熱傳係數的主要參數，鰭片間距較寬時，熱傳係數較高，間距16 mm直線鰭片比間距7 mm直線鰭片熱傳係數高79 ~ 114 %。而鰭片高度並無法顯著影響鰭片熱傳係數，高度15 mm直線鰭片平均熱傳係數比間距7 mm直線鰭片僅高6 ~ 20 %。斷續型鰭片單一鰭片長度，對斷續型鰭片平均熱傳係數並無顯著影響，且斷續型鰭片和有相同鰭片間距的間距7 mm直線鰭片平均熱傳係數約相同。 An experimental investigation of natural convection heat transfer in nine vertical fins having the same frontal area is described. There are four types of fin which are flat plate fin, straight fin, offset strip fin and offset strip increase in length fin with different space, height and length of discrete plates. Flat plate fin has highest heat transfer coefficient and smallest heat transfer rate in all fins. The chief geometric feature for effecting on heat transfer coefficient is fin space. Larger fin space leads to higher heat transfer coefficient. Heat transfer coefficient for 16 mm space of straight fin is better then 7 mm space by 79 ~ 114 %. Fin height effects on heat transfer coefficient insignificantly. Heat transfer coefficient for 15 mm height of straight fin is better then 7 mm space by 6 ~ 20 %. Length of discrete plates of offset strip fin effects on heat transfer coefficient insignificantly. In the same fin space, the heat transfer coefficient of offset strip fin is almost equal to the 7 mm space of straight fin.
