Fig. 1. Water film cooling heat transfer model

Fig. 2. Schematic of the element cross-section

Fig. 3. Comparison of the simulated and experimental results^［6］ of the average temperature of the test plate

Fig. 4. Absorption coefficient of water^［17］

Fig. 5. Infrared transmittance of water film with different thicknesses

Fig. 6. Images of different types of materials and their emissivity： 1-resin plate，2-anodized aluminum plate，3-steel plate，4-galvanized steel plate

Fig. 7. Before spraying：(a) thermocouple temperature；(b) infrared temperature

Fig. 8. Spraying process：(a) thermocouple temperature；(b) infrared temperature

Fig. 9. Backside of the plates after spraying：(a) thermocouple temperature；(b) infrared temperature

Fig. 10. Schematic diagram of radiation transfer in water film

Fig. 11. Temperature distribution of solid surface and free surface of water film

Fig. 12. Infrared radiation intensity for water film considered as semi-transparent and non-transparent medium

Fig. 13. Results and relative errors of various calculation methods under different spray flow conditions

Fig. 14. Results and relative errors of various calculation methods under different inclination angles

Fig. 15. Results and relative errors of various calculation methods at different spraying time conditions