Measuring time-resolved heat transfer fluctuations on a heated-thin foil in a turbulent channel airflow

TL;DR

This paper introduces an experimental method for high-resolution, time-resolved heat transfer measurements on a heated foil in turbulent airflow, addressing challenges like thermal inertia and noise to improve turbulence studies.

Contribution

The paper presents a novel experimental setup combining a heated thin foil with high-speed infrared thermography for detailed turbulence-related heat transfer measurements.

Findings

Successful implementation of high-quality, time-resolved heat transfer data acquisition.

Identification of key design considerations for accurate wall-based turbulence measurements.

Potential applications in flow control and turbulence modeling.

Abstract

We present an experimental setup to perform time-resolved convective heat transfer measurements in a turbulent channel flow with air as the working fluid. We employ a heated thin foil coupled with high-speed infrared thermography. The measurement technique is challenged by the thermal inertia of the foil, the high frequency of turbulent fluctuations, and the measurement noise of the infrared camera. We discuss in detail the advantages and drawbacks of all the design choices that were made, thereby providing a successful implementation strategy to obtain high-quality data. This experimental approach could be useful for experimental studies employing wall-based measurements of turbulence, such as flow control applications in wall-bounded turbulence.