Measuring the distribution of the wall temperature and static pressure in a narrow flow gap using a sensor-embedded thin plate

Compact thermo-fluidic systems with complex and narrow gap flow passages, such as heat exchangers, are attractive for use in high energy efficiency applications. However, the narrow gap flow passage limits the experimental evaluations as a result of the size of the commercial sensors and the numerical evaluations of the full model due to massive computational meshes. This paper presents a new method to measure the distribution of the static pressure and wall temperature in the narrow gap. The 300 μm-thick stainless steel plate embedded with thermocouple temperature sensors and pressure tapping holes connected with microchannels is fabricated, and the temperature and pressure measurements are calibrated through comparisons with commercial sensors. In the experimental evaluation, the 23 flat plates are stacked with a narrow gap and the sensor-embedded plate is placed in the center. Then, the stacked plate thermo-fluidic system is installed in a wind tunnel. The measurement of the static pressure and wall temperature distributions in the narrow gap is performed successfully for the increased inlet flow velocities. The static pressures are measured at five different micro tapping holes, and the measurements exhibit a standard deviation of ±3.51 Pa for the same inlet velocity. Furthermore, the wall temperatures have good agreement with the reference temperatures measured at the inlet.