Multicolor particle shadow accelerometry

Area of Science:

• Fluid dynamics
• Experimental fluid mechanics
• Particle imaging velocimetry

Background:

• Accurate measurement of local acceleration is crucial for understanding complex fluid flows.
• Eulerian measurements provide direct insight into fluid particle motion.
• Existing techniques may have limitations in capturing high-frequency acceleration data.

Purpose of the Study:

• To extend multicolor particle shadow velocimetry (CPSV) for Eulerian local acceleration measurement.
• To validate the extended CPSV technique in controlled and turbulent flow environments.
• To assess the impact of time delay on acceleration estimation accuracy.

Main Methods:

• Development and application of multicolor particle shadow velocimetry (CPSV).
• Validation experiments involving a pendulous disk with unsteady rotation.
• Application to a fully-developed turbulent pipe flow.
• Comparison with accelerometer data and particle image accelerometry (PIA).

Main Results:

• CPSV successfully measured angular velocity and acceleration profiles in unsteady rotation.
• Measurements of local acceleration standard deviation in turbulent pipe flow showed favorable agreement with prior studies.
• CPSV demonstrated comparable results to particle image accelerometry (PIA).

Conclusions:

• The extended CPSV technique is a viable method for Eulerian local acceleration measurements.
• CPSV offers a promising alternative for detailed flow analysis, particularly in turbulent regimes.
• Understanding the effect of time delay is important for optimizing acceleration estimates.