Measuring microscale flow features I — Lesson 1

This lesson covers the concept of micro PIV (Particle Image Velocimetry) analysis in fluid mechanics. It delves into the operational principles, methods, and post-processing of images in this measurement technique. The lesson explains how PIV is a non-invasive technique that doesn't require disturbing the flow field. It also discusses the importance of seeding particles in the flow and their characteristics. The lesson further elaborates on the use of PIV in microscale transport processes and the components and techniques involved in a micro PIV setup. For instance, it explains how volume illumination is preferred over zone illumination in micro analysis. The lesson also covers the importance of high special resolution and the role of light sources in the process.

Video Highlights

01:42 - Non-invasive nature of PIV measurement and the importance of seeding particles in the flow
08:16 - Important features of micro PIV analysis, including the use of volume illumination and high special resolution
12:31 - Explanation of the micro PIV setup, including the use of a syringe pump, micro fluidic channel, and inverted microscope
29:36 - Importance of seeded particles in micro PIV analysis and the characteristics these particles should have
40:43 - Use of CCD or CMOS cameras in micro PIV analysis for high-speed imaging
43:35 - Cross-correlation algorithm used in micro PIV analysis for velocity calculation

Key Takeaways

- Micro PIV analysis is a crucial measurement technique in fluid mechanics that allows for the characterization of flow at a microscale.
- PIV is a non-invasive technique that doesn't require disturbing the flow field, making it advantageous for certain applications.
- Seeding particles in the flow is an essential part of the process, and these particles must possess certain characteristics.
- In micro analysis, volume illumination is preferred over zone illumination due to the micro-sized length scale.
- High special resolution is crucial for accurately tracking and quantifying the flow parameters.
- Light sources play a significant role in the process, with high-powered laser beams with short pulsed duration being preferred.