For diesel sprays, the primary breakup processes are only rarely understood due to the high optical density and the resulting difficulties to measure them with extremely high spatial and sufficient temporal resolution. The Optical Connectivity Method (OCM) has been proposed in the last years to allow the determination of the breakup length of the connected liquid core, thus giving a measurement quantity of the primary breakup. In this work, an improved optical setup of the OCM is applied to a three-hole test injector nozzle where several measurement techniques are compared currently under well-defined conditions up to 100 MPa injection pressure. In this work, the direct comparison with X-Ray measurements done at the Advanced Photon Source of the Argonne National Laboratory will be described. This allows an evaluation of the OCM technique and a comparison of the different measurement quantities in the first 500 µm range of the spray. The structure of the spray is measured by X-Ray phase contrast imaging and the fuel mass distribution is measured by X-Ray absorption imaging. A detailed comparison of the two X-Ray techniques and the OCM technique has been possible for the first time. It is found that the measurement data of the spray near field are very congruent with all three methods. Due to this comparison, the measurement of the non-perturbed length, which describes the distance from the nozzle orifice up to the point where the formation of surface disturbances is starting, by the OCM is validated for the first time. Within this non-perturbed length of the spray, the OCM signal is weak before it starts to illuminate from the scattering of the perturbed surface. Thus, the OCM technique can deliver two characteristic length scales, the non-perturbed length and the breakup length, characterizing the primary spray breakup.

对于柴油喷雾器，主要的分解过程由于光密度高以及由此而来的很难以极高的空间分辨率和足够的时间分辨率进行测量而很少被理解。近年来，已经提出了光连接方法（OCM），以允许确定所连接的液芯的破裂长度，从而给出一次破裂的测量量。在这项工作中，将OCM的改进的光学装置应用于三孔测试喷射器喷嘴，目前在明确定义的条件下（高达100 MPa的喷射压力）比较了几种测量技术。在这项工作中，将描述与在Argonne国家实验室的高级光子源处进行的X射线测量结果的直接比较。这样就可以对OCM技术进行评估，并可以在喷雾的前500 µm范围内比较不同的测量量。喷雾的结构通过X射线相衬成像测量，并且燃料质量分布通过X射线吸收成像测量。首次有可能对两种X射线技术和OCM技术进行详细比较。发现喷雾近场的测量数据与所有三种方法都非常一致。由于该比较，OCP首次验证了非扰动长度的测量，该长度描述了从喷嘴孔到开始形成表面扰动点的距离。在喷雾的这个不受干扰的长度内，OCM信号在被扰动表面的散射开始照亮之前是微弱的。因此，OCM技术可以提供两个特征长度刻度，即非扰动长度和破碎长度，这是一次喷雾破碎的特征。