A new engine block with optical access has been designed and manufactured capable of running up to 3000 r/min with the same specification as the unmodified engine. The optical window allowed access to the full length of the liner over a width of 25 mm to investigate the lubricant flow and cavitation at contact point between the rings and cylinder-liner. In addition, it allowed good access into the combustion chamber to allow charged flow, spray and combustion visualisation and measurements using different optical methods. New custom engine management system with build in LabView allowed for the precise full control of the engine. The design of the new optical engine was a great success in producing high quality images of lubricant flow, cavitation formation and development at contact point at different engine speeds ranging from 208 to 3000 r/min and lubricant temperatures (30°C–70°C) using a high-speed camera. The results under motorised operation confirmed that there was no cavitation at contact points during the intake/exhaust strokes due to low in-cylinder presure, while during compression/expansion strokes, with high in-cylinder pressure, considerable cavities were observed, in particular, during the compression stroke. Lubricant temperatures had the effect of promoting cavities both in their intensity and covered ring area up to 50°C as expected. Beyond that, although the cavitation intensity increases further with temperature, its area reduces due to possible collapse of the cavitating bubbles at higher temperature. The change of engine speed from 208 to 800 r/min increased cavitating area considerably by 52% of the ring area and was further increased by 19% at 1000 r/min. After that, the results showed very small increase in cavitation area (1.3% at 2000 r/min) with similar intensity and distribution across the ring.

设计并制造了一种带有光学通道的新型发动机缸体，该发动机缸体的运行速度高达3000 r / min，并且规格与未经修改的发动机相同。光学窗口允许在25 mm的宽度上进入衬套的全长，以研究在环和气缸套之间的接触点处的润滑剂流动和气蚀现象。此外，它还可以很好地进入燃烧室，从而可以使用不同的光学方法对带电的流量，喷雾和燃烧进行可视化和测量。内置在LabView中的新的自定义引擎管理系统允许对引擎进行精确的完全控制。新型光学引擎的设计在产生高质量的润滑油流动图像方面取得了巨大的成功，使用高速相机，在发动机转速从208至3000 r / min和润滑剂温度（30°C–70°C）的不同转速下，接触点处的气穴形成和发展。电动操作下的结果证实，由于缸内压力低，在进气/排气冲程期间接触点上没有气穴，而在缸内压力高的压缩/膨胀冲程期间，观察到相当大的空穴，特别是，在压缩冲程中。如预期的那样，润滑剂温度具有促进空腔强度和覆盖环面积的作用，最高可达50°C。除此之外，尽管空化强度随温度进一步增加，但由于空化气泡在较高温度下可能塌陷，其面积减小了。发动机转速从208转为800 r / min时，空化面积显着增加了环面积的52％，在1000 r / min时进一步增加了19％。此后，结果表明空化面积的增加很小（在2000 r / min时为1.3％），强度和环上的分布相似。