On the Implementation of Simultaneous Multi-Frequency Excitations and Measurements for Electrical Impedance...

Area of Science:

• Fluid dynamics
• Electrical engineering
• Imaging science

Background:

• Investigating rapidly evolving flow patterns in high-pressure, high-temperature environments necessitates high-speed, non-intrusive imaging.
• Electrical Impedance Tomography (EIT) reconstructs flow admittivity from peripheral electrical measurements.

Purpose of the Study:

• To develop and validate a high-speed EIT system for analyzing dynamic flow patterns.
• To demonstrate the feasibility of simultaneous multi-frequency excitations and measurements for increased imaging rates.

Main Methods:

• Theoretical framework for a 16-electrode simultaneous EIT system.
• Implementation using a field-programmable gate array (FPGA) data acquisition system.
• Analysis of uncertainty propagation and experimental validation with fifteen simultaneous signals.

Main Results:

• Successful retrieval of signals at an experimental imaging rate of 1953 frames per second.
• Signal-to-noise ratios ranging from 59.6 to 69.1 dB, dependent on frequency.
• Demonstration of simultaneous multi-frequency EIT's capability to significantly enhance imaging speed.

Conclusions:

• Simultaneous multi-frequency excitations and measurements are a viable strategy for high-speed EIT.
• The developed FPGA-based EIT system effectively captures dynamic flow characteristics.
• This technique shows significant promise for industrial applications requiring rapid flow analysis.