Figure 1

Flow visualization and heat transfer results of critical composition experiments. (a) Schematics of the three-layer testing environment. (b) Phase diagram and flow visualization images. Photos on the left column are the short heater visualizations (m″ = 284 kg/m²s, T_in = 14.1 °C), long heater visualizations are on the right column (m″ = 208 kg/m²s, T_in = 11.4 °C). The system’s location on the phase diagram is approximated using the average wall temperature. For the long heater case with Q″ = 73.8 W/cm², T_w = 79.3 °C, its location is marked at the topmost location on the phase diagram. (c) Long heater average heat transfer coefficient results at m″ = 208 kg/m²s, m″_water = 190 kg/m²s. (d) Short heater average heat transfer coefficients results at m″ = 284 kg/m²s, m″_water = 274 kg/m²s. (e) Pressure drop results for the long heater at m″ = 208 kg/m²s. Full quality flow visualization images can be found in Supplementary Fig. 7.