由於JP-8燃油與汽油相比具有高蒸餾溫度、低揮發性、密度、黏度及表面張力較高之特性，相對的有更高的安全性，對於軍事等特殊用途可以有特殊考量，但是應用在火花點火引擎上還是需經過相當之分析診測，並且實驗數值對於低壓噴嘴噴霧之模擬校正也相當重要，故本研究對於JP-8的替代性與其在不同油溫之噴霧特性進行診測並與異辛烷比較，首先進行燃油特性曲線量測，之後利用雷射光學視流法取得其噴霧定性或定量資訊，其中包含噴霧平均影像、噴霧貫穿深度、噴霧速度，並利用雷射粒徑分析儀取得其平均粒徑及體積粒徑分布百分比。結果發現JP-8燃油流量比異辛烷大，並且其流量隨著燃油溫度提高而略微下降，故在實際應用時必須調整噴嘴控制單元。在噴霧影像分析上，由於JP-8之黏滯係數與表面張力較大，造成噴霧相較於異辛烷較不易霧化，液柱較晚破裂，且JP-8噴霧之貫穿距離較異辛烷短，由影像測速可發現此是由於噴霧速度分布較異辛烷慢，但整體差距並不大。在粒徑分析的部份，JP-8之粒徑資訊與近代文獻相近，在不同油溫的情況下，其SMD介於80至115μm之間。由上述資訊可得知，本研究所使用之燃油噴嘴在應用JP-8時其噴霧特性與異辛烷差異並不顯著，並且利用燃油加溫可提昇燃油霧化程度，提昇其應用於火花點火引擎之可行性。

The purpose of the study of this thesis is to investigate into the feasibility of using JP-8 fuel in PFI injectors for spark ignition (SI) engines. Since JP-8 fuel when compared with gasoline has a higher distillation temperature, density, viscosity, surface tension, and lower volatility, so it requires detailed analysis for application in spark-ignition engines. In addition, the experimental data of fundamental importance for the spray simulation of low pressure injectors. In this study, the spray characteristics of JP-8 fuel unheated and heated at different line temperatures are measured and compared with the spray characteristics of iso-octane. The experiments include fuel flow rate tests, laser quantitative flow visualization of fuel spray and penetration characteristics, particle image velocimetry measurements of spray velocity, Malvern particle size analysis, etc. In the same operation conditions, the mean fuel flow rate of JP-8 fuel is found higher than that for iso-octane and becomes slightly lower with increase of the JP-8 fuel line temperature. For practical applications, the flow rate must be carefully adjusted in the ECU if JP-8 is to be used to replace gasoline. For the part of spray visualization, due to higher viscosity and surface tension of JP-8, less JP-8 is atomized into spray than iso-octane. The spray tip penetration of JP-8 is shorter than that of iso-octane. For particle size analysis, the particle size of JP-8 spray of different fuel line temperatures is ranging from about 80 to 115μm, and the particle size of gasoline at room temperature is about 90 to 120μm. As mention above, the difference of spray characteristics between the fuel injector using JP-8 and that using iso-octane is insignificant, so in terms of fuel atomization and spray for PFI injectors, it is feasible of using JP-8 to replace gasoline, especially when slightly heated.

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