Development of a sensor for liquid film thickness measurements during annular flow in microchannels

Author(s)

Baptistella, Victor Eduardo Corte ; Guo, Zhaorui ; Lee, Minhyeok ; Ribatski, Gherhardt ; Suzuki, Yuji

• Document type: Journal article
• Source: EXPERIMENTS IN FLUIDS; v. 65, n. 11, p. 12-pg., 2024-11-01.

Abstract

A conductance-based sensor to measure liquid film thickness during annular two-phase flows in microchannels has been developed in the present study. The liquid film plays an important role on the characterization of two-phase annular flows. The mean thickness and the presence of interfacial waves influence the heat transfer rate, critical heat flux and pressure drop. The proposed sensor has a ring-shaped design and targets the measurement of films thinner than 50 mu m in order to provide detailed information on the liquid film behavior during wall dryout events. It is fabricated on a TEMPAX wafer with micro-electro-mechanical systems (MEMS) technologies. The performance of the prototype device is assessed by using aqueous solutions of known conductivity and imposing liquid films with prescribed thicknesses above the sensor. The effects of the geometrical parameters on the sensor behavior are discussed with the aid of numerical simulation and experimental results. It is found that increasing the size of the electrodes increases the measured electrical signals, while increasing the spacing between the electrodes decreases the measured signal. (AU)

• FAPESP's process: 20/10923-2 - Evaluation of the hydrodynamic behavior and the heat transfer mechanisms during flow boiling in microchannels under conditions close to the surface dryout
• Grantee: Victor Eduardo Corte Baptistella
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 16/09509-1 - Phase change heat transfer processes of high performance applied to solar energy recovery
• Grantee: Gherhardt Ribatski
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 21/13161-9 - Integration of liquid film thickness microsensors, thermocouples and thin film heaters for annular flow investigations in microchannels
• Grantee: Victor Eduardo Corte Baptistella
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)