中文摘要：

基于斯特林发动机喷雾特性，建立了斯特林喷嘴的数学物理模型，模拟了冷态工况下低硫柴油（ULSD）和二甲醚（DME）2种不同燃料在不同背压下斯特林发动机的喷雾过程，并与实验结果进行了对比分析．研究发现，背压的增大对ULSD的雾化具有促进作用，对DME的雾化具有抑制作用；相同流量和背压下，DME的贯距比ULSD小，喷雾锥角比ULSD大．当背压增加较大时，继续提高背压时喷霖锥角的影响减弱。且晴霖锥角随著流量的增大而增大．

英文摘要：

According to the practical spray characteristics of a Stirling engine, the mathematical and physical model was built and solved. By comparing with experiment data, the model was verified and validated. On this base, the spray characteristic of Stirling engine by using uhralow sulfur diesel （ULSD） fuel and dimethyl ether （DME） under cooling condition were simulated and analyzed. The results show that increasing back pressure can improve the spray characteristics although it could restrain the DME atomization. Compared with ULSD, DME provides shorter tip penetration and wider cone angle under the same mass flow rate and back pressure. With the increase of back pressure, the spray cone angle tends to increase whereas high ambient pressure has slight influence on spray cone angle when the back pressure exceeds a certain high value.