ENGINE COMBUSTION NETWORK (ECN): MEASUREMENTS OF NOZZLE GEOMETRY AND HYDRAULIC BEHAVIOR
ENGINE COMBUSTION NETWORK (ECN): MEASUREMENTS OF NOZZLE GEOMETRY AND HYDRAULIC BEHAVIOR
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DOI：
10.1615/atomizspr.2013006309
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发表时间：
2012-01-01
影响因子：
1.2
通讯作者：
Bazyn, Tim
中科院分区：
文献类型：
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作者：
Kastengren, Alan L.;Tilocco, F. Zak;Bazyn, Tim
尽管喷雾对发动机燃烧的重要性，但喷雾行为对未知喷嘴几何形状影响的敏感性阻碍了理解。发动机燃烧网络（ECN）合作的重点是克服这一障碍，喷雾研究的重点是一组名义上相同的柴油喷射器。使用X射线断层扫描、X射线相衬成像、硅胶成型和光学显微镜对4个ECN喷雾A注射器（直径90 μ m，轴向单孔喷嘴）的喷嘴几何形状进行了详细测量。还测量了喷嘴的针阀运动（轴向和横向）和水力性能。喷嘴几何形状的测量结果表明，所有喷嘴孔均偏离针和囊的轴线。这种偏移在喷嘴孔的入口条件中产生不对称性，其在喷嘴之间变化。喷嘴型线明显偏离标称规格，所有喷油器中喷嘴出口附近的喷嘴孔突然收敛。喷嘴直径测量显示直径小于标称规格，喷油器之间存在显著差异。针阀升程测量表明针阀在轴向和横向运动中具有振荡行为。喷嘴的水力特性证明了内部几何形状（出口直径）对动量和质量流率的影响。
Despite the importance of sprays to engine combustion, understanding has been hampered by the sensitivity of spray behavior to unknown nozzle geometry effects. The Engine Combustion Network (ECN) collaboration has focused on overcoming this impediment to spray research by focusing on a set of nominally identical diesel injectors. Detailed measurements of the nozzle geometry for the four ECN Spray A injectors (90 mu m diameter, axial single-hole nozzles) have been performed using x-ray tomography, x-ray phase-contrast imaging, silicone molding, and optical microscopy. Measurements of the needle motions (axial and lateral) and hydraulic performance of the nozzles have also been performed. Measurements of the nozzle geometry show that all of the nozzle holes are offset from the axis of the needle and sac. This offset creates an asymmetry in the inlet condition of the nozzle hole, which varies from nozzle to nozzle. The nozzle profile deviates significantly from the nominal specification, with an abrupt convergence of the nozzle holes near the nozzle exit seen in all of the injectors. Nozzle diameter measurements show a smaller diameter than the nominal specification, with significant differences between the injectors. Needle lift measurements show oscillatory behavior in both the axial and lateral motions of the needle. The hydraulic characterization of the nozzles demonstrates the impact of internal geometry (outlet diameter) on momentum and mass flow rate.