Precise Measurement of Moving Object by Moiré-Based Image Processing Technique

Moiré images that are generally termed as moiré fringes have been generated due to the interference of two repetitive gratings. These patterns can be applied to many uses in metrology such as the measurements of surface profilometry of aerofoil, stress-strain effects, thermal deformation and so on. Moreover, 3D surface reconstruction as well as movement characterization of linearly and rotary moving objects can be visualized and identified by the moiré imaging technique. Recently it is approached as an emerging tool in the fields of biotechnology-particularly in biomechanics, nanotechnology, broadband communication and optoelectronics as well. Conventional Moiré interferometry evaluates the interference of two light waves being reflected on a reference surface and the object to be profiled. However, satisfactions in the requirements for the current significant issues in obtaining accurate measurements regarding the information of the movements as well as the dimensional deformations of objects dealing with the online inspection in micro-level and nano-level are still challenging. Particularly, for the demand of the present real-time auto-inspection of different precise information of movements objects statistically and dynamically. In that case single light wave system makes the moiré sensing system easier and applicable in real-time imaging. Furthermore, avoiding the employment of expensive conventional imaging facilities in 3-D measurement in mechanical as well as bio-mechanical systems has become a critical problem to be tackled. Therefore, research has been conducted focusing on the objective of developing a simple but precise measuring tool based on a single wave moiré imaging technique for multidimensional motion sensing by employing simple image processing approaches. An experimental set-up with a small CMOS camera has been developed capable of measuring the motion of an object by using a simply ink-printed straight optical grating lines attached to the moving objects. Several model experiments have been conducted for getting the information of movements of an object by adopting several mouse click options only on the moiré image visible at the computer screen. After getting information of the moiré image by the proposed technique, the movements of the object have been accurately identified. The system has been found simple and faster compared to the other conventional methods as well.

Effect of Non-Equilibrium Condensation of Moist Air on Unsteady Behaviour of Shock Waves around a Circular Arc Blade

在在机翼附近的接近音速的流动的不稳定的现象在扇子，压缩机片和蝴蝶阀门的流动地里被观察，并且这经常引起象 aeroacoustic 噪音那样的严重问题，颤动。在蒸汽在主要流动被包含的接近音速或超声的流动，流动的快速的扩大可以产生一个非平衡冷凝作用。然而，在机翼附近的接近音速的内部流动上的非平衡冷凝作用的效果还没令人满意地被澄清了。在现在的学习，圆形的弧片上的自我刺激的冲击波摆动上的潮湿的空气的非平衡冷凝作用的效果数字地被调查。结果证明在有非平衡冷凝作用的情况中，没有非平衡冷凝作用，流动摆动的频率变得比那些小。

The Effect of Non-Equilibrium Condensation on Supersonic Air Flows over Rectangular Cavities

数字模拟在开的、矩形的洞上为超声的二维的流动被执行了(length-to-depth 比率是 L/D = 1.0 和 3.0 ) 数以便为流动马赫在洞附近在超声的内部流动上调查潮湿的空气的非平衡冷凝作用的效果 1.83 在洞入口。在现在的计算调查，压缩流动被潮湿的空气的扩大在一张 Laval 嘴生产。计算结果证明没有冷凝作用，在上游的旅行压缩波浪变得比那些弱。因而，更弱的压缩波浪不能强烈使 shear 层激动，没有冷凝作用，在洞的摆动的振幅变得比那些小。在 L/D = 的情况下的非平衡冷凝作用的出现 1.0 强烈与 L/D = 相比在洞影响了摆动的振幅和频率 3.0。

Jet Screech Reduction with Perforated Flat Reflector

在现在的试验性的学习，调查被执行了与不同穿孔扁平的反射镜评估喷气尖叫的新控制技术的性能。主要，多孔的扁平的反射镜的二种类型在实验被使用了。一个反射镜(reflector-V ) 为放对喷气轴垂直的反射镜表面设计了，当时，反射镜(reflector-H ) 的另一种类型为放对喷气轴水平的思考表面设计了。在两个盒子中，反射镜被放在嘴(有一致代表性的区域的基础试管) 出口。当 reflector-H 的直径是 10D 时， reflector-V 的直径是 15D。reflector-V 的多孔的区域为 D 显示了嘴出口的直径的 reflector-H 是 6D 和 4.5D。在嘴的出口的反射镜的放置在嘴出口减少健全压力。因此，减弱的声音不能在嘴出口使不稳定的骚乱激动，最后，反馈机制的环消失喷气尖叫的产生被取消。在 reflector-V 的多孔的表面的背方面定位的吸空间改进尖叫控制技术的效率。在 reflector-H 的情况中，然而，反馈循环的感受性进程被在有效吃惊前面以及在嘴出口减少骚乱控制了。建议方法的表演与一个扁平的反射镜概念被验证，在喷气尖叫抑制的好性能在多孔的反射镜的情况中被证实了。