水冲压发动机试验水燃比选择方法

 水燃比是水冲压发动机的重要工作参数。水燃比过大易造成内流场温度降低,实际工作中低温可能引起水蒸汽液化和金属/水反应停止,以致降低发动机性能。为减少这类情况的出现,针对两次进水的水冲压发动机,提出了试验总水燃比及一、二次水燃比选择方法。该方法以发动机热力计算的最优理论水燃比为基础，考虑试验过程中实际热损失的影响对其进行了修正。针对不同水燃比的影响,对某型试验水冲压发动机进行了地面直连试验研究,结果显示存在最佳总水燃比及一次水燃比使发动机性能达到最优,同时证明了该水燃比选择方法合理可行。

Water/Fuel Ratio Selection Method in Water Ramjet Engine Test

Water/fuel ratio is an important working parameter of water ramjet engines. A high water/fuel ratio tends to result in a low temperature flow in the water ramjets. When the temperature drops severely, condensation of water steam may occur and the reaction of steam and metal may stop, which will reduce the engine performance as a result. Taking the effects of these two factors into account, a method to select the overall and primary water/fuel ratios is investigated to obtain a high engine performance. For the configuration of the discussed water ramjet, two water intakes are positioned along the combustion chamber. The selection is based on a theoretical optimum water/fuel ratio from thermodynamic calculation, which is then modified in consideration of heat loss in real experiments. Ground direct-connect experiments are conducted under different water/fuel ratios. The results show that optimal overall and primary water/fuel ratios exist, and the method to predict them is also verified.