The effects of blending ratio on mixtures of an alcohol-to-jet (ATJ) fuel and a conventional petroleum-derived fuel on first stage ignition and overall ignition delay are examined at engine-relevant ambient conditions. Experiments are conducted in a high-temperature pressure vessel that maintains a small flow of dry air at the desired temperature (825 K and 900 K) and pressure (6 MPa and 9 MPa) for fuel injections from a custom single-hole, axially-oriented injector, representing medium (7.5 mg) and high (10 mg) engine loading. Formaldehyde, imaged using planar laser-induced fluorescence, is measured at discrete time steps throughout the first and second stage ignition process and is used as a marker of unburned short-chain hydrocarbons formed after the initial breakdown of the fuel. The formaldehyde images are used to calculate the first stage ignition delay for each ambient and fuel loading condition. Chemiluminescence imaging of excited hydroxyl radical at 75 kHz is used to determine the overall ignition delay. At all conditions, increased volume fraction of ATJ resulted in longer, but non-linearly increasing, overall ignition delay. Across all of the blends, first stage ignition delay accounted for about 15% of the increase in overall ignition delay compared to the military's aviation kerosene, F-24, which is Jet A with additives, while extended first stage ignition duration accounted for 85% of the increase. It is observed that blends consisting of 0–60% by volume of the low cetane number ATJ fuel produced nearly identical first stage ignition delays. These results will inform the development of ignition models that can capture the non-linear effects of fuel blending on ignition processes.

在发动机相关的环境条件下，研究了混合比对醇喷（ATJ）燃料和常规石油衍生燃料的混合物对第一阶段点火和总点火延迟的影响。实验是在高温压力容器中进行的，该容器在期望的温度（825 K和900 K）和压力（6 MPa和9 MPa）下保持少量的干燥空气流，以从定制的单孔轴向喷射燃料。定向喷油器，代表中等（7.5毫克）和高（10毫克）发动机负载。在整个第一阶段和第二阶段点火过程中，使用离散的时间步长测量使用平面激光诱导的荧光成像的甲醛，并将其用作燃料初次分解后形成的未燃烧短链碳氢化合物的标志物。甲醛图像用于计算每种环境和燃料装载条件的第一阶段点火延迟。75 kHz激发的羟基自由基的化学发光成像可用于确定总体点火延迟。在所有条件下，ATJ体积分数的增加会导致总点火延迟更长，但呈非线性增加。在所有混合物中，与军用航空煤油F-24（带有添加剂的Jet A）相比，第一阶段点火延迟约占总点火延迟增加的15％，而延长的第一阶段点火持续时间占85％。的增加。可以观察到，由低十六烷值ATJ燃料的0-60％（体积）组成的混合物产生了几乎相同的第一级点火延迟。