Abstract The diesel engine parameters are more compatible with diesel fuel operation. However optimization of engine parameters for dairy scum biodiesel operation in diesel engine is highly pronounced as dairy scum biodiesel has higher viscosity and lesser heating value when compared to petroleum diesel. In the present study, nozzle hole (NH) geometry and engine parameters namely injector opening pressure (IOP), injection timing (IT), compression ratio (CR) are modified to appraise (optimize) the diesel engine performance. At the end optimized engine parameters (IOP: 230 bar, IT: 26 deg.bTDC, CR: 18, NH: 5 holes) are carried further to investigate the effect of piston bowl geometry on diesel engine performance operated with B20 (20% biodiesel+ 80% diesel) fuel blend. The experimental study revealed that the modified engine with Re-entrant Toroidal Piston Bowl Geometry (RTPBG) showed improved performance, combustion and emission characteristics when compared with standard engine (B20-SE) and modified engine (ME) with different piston bowl geometries, namely Hemispherical Piston Bowl Geometry (HPBG), Straight Sided Piston Bowl Geometry (SSPBG) and Toroidal Piston Bowl Geometry (TPBG). This improvement could be attributed to improved fuel atomization, smaller size droplets, increased cylinder temperature, swirl and squish, turbulent kinetic energy of the charge during combustion.

中文翻译：

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使用 B20 混合燃料运行的具有不同活塞碗几何形状的标准发动机和改进发动机的比较研究

摘要 柴油机参数与柴油运行更加兼容。然而，由于与石油柴油相比，乳渣生物柴油具有更高的粘度和更低的热值，因此柴油发动机中乳渣生物柴油操作的发动机参数的优化非常显着。在本研究中，喷嘴孔 (NH) 几何形状和发动机参数，即喷油器开启压力 (IOP)、喷射正时 (IT)、压缩比 (CR) 被修改以评估（优化）柴油发动机性能。最后，优化发动机参数（IOP：230 bar，IT：26 deg.bTDC，CR：18，NH：5 孔）进一步研究活塞碗几何形状对使用 B20（20% 生物柴油+ 80% 柴油）燃料混合物。实验研究表明，与具有不同活塞碗几何形状的标准发动机 (B20-SE) 和改进发动机 (ME) 相比，具有 Reentrant Toroidal Piston Bowl Geometry (RTPBG) 的改进发动机表现出更好的性能、燃烧和排放特性，即半球形活塞碗几何形状 (HPBG)、直边活塞碗几何形状 (SSPBG) 和环形活塞碗几何形状 (TPBG)。这种改进可归因于改进的燃料雾化、较小尺寸的液滴、增加的气缸温度、涡流和挤压、燃烧期间充气的湍流动能。即半球形活塞碗几何形状 (HPBG)、直边活塞碗几何形状 (SSPBG) 和环形活塞碗几何形状 (TPBG)。这种改进可归因于改进的燃料雾化、较小尺寸的液滴、增加的气缸温度、涡流和挤压、燃烧期间充气的湍流动能。即半球形活塞碗几何形状 (HPBG)、直边活塞碗几何形状 (SSPBG) 和环形活塞碗几何形状 (TPBG)。这种改进可归因于改进的燃料雾化、更小尺寸的液滴、增加的气缸温度、涡流和挤压、燃烧期间充气的湍流动能。