Preliminary test of an ultrasonic liquid film sensor for high-temperature steam–water two-phase flow experiments

Figures & data

Figure 1. Schematic view of liquid film sensor.

Figure 2. Sensor casing inside which the piezoelectric element was attached.

Figure 3. Confirmation of temperature rise due to laser welding: (a) measurement point locations; (b) temperature change due to laser welding.

Figure 4. Micro photograph of the laser welded part.

Figure 5. Instrument configuration: (a) connection with the instrument; (b) configuration for observing the pulse reflected from the casing surface; (c), (d) configuration for observing the pulse reflected from the liquid film surface.

Figure 6. Waveforms obtained on an oscilloscope: (a) for the fixed nozzle position; (b) for the moving nozzle position.

Figure 7. Time series liquid film thickness: (a) for the fixed nozzle position; (b) for the moving nozzle position.

Figure 8. Frequency characteristic of the liquid film sensor.

Figure 9. Amplitude decrease by reflection and transmission.

Table 1. Material properties at room temperature (20 °C).

	Density	Speed of	Acoustic
	(kg/m^3)	sound (m/s)	impedance (kg/m^2s)
Stainless steel	7980	5.81×10^3	4.64×10^7
Water	998	1.48×10^3	1.48×10^6
Air	1.21	3.44×10^2	4.14×10^2

Figure 10. Confirmation of amplitude calculated by the acoustic impedance.

Table 2. Material properties at 286 °C.

	Density	Speed of	Acoustic
	(kg/m^3)	sound (m/s)	impedance (kg/m^2s)
Stainless steel	7880	5.61×10^3	4.42×10^7
Water	740	9.87×10^2	7.30×10^5
Steam	36.5	5.01×10^2	1.83×10^4

Figure 11. Predicted amplitude ratio at 286 °C.