THERMAL RADIATION ABSORPTION BY WATER CURTAINS. PART 2

This paper deals with the problem of simulation of water curtains used as fire protection walls. The central objective of the study is to characterize the interaction of the water spray with thermal radiation. Radiative properties for the droplets are calculated applying the geometrical optics approximation. The calculations executed on the basis of earlier developed mathematical model allowed obtaining more precise formulas for a transmittance of a water spherical droplet. These formulas have been used to calculate transmission spectra of water curtains for heat radiation of a near infrared range 1–10 -m. According to the received formulas, the transmittance of a water curtain depends on the size of droplets, specific water loading and curtain thickness. The form of transmission spectra of a water curtain is defined by dependence of an absorption coefficient of water on a radiation wavelength. The analysis of spectra from some references allowed concluding that this dependence does not influence their form owing to low specific water loading. Its spectral features are defined by the gas components of water curtains, and it is the main reason of discrepancy of calculated spectra of this work and some references. Calculated dependences of a water curtain transmittance on the water loading demonstrate acceptable agreement with the results presented in some other references.