Efficient transmission calculations for polydisperse water sprays using spectral scaling

Analytical expressions are developed to scale the extinction, scattering and absorption coefficients as a function of the Sauter mean diameter for polydisperse water sprays in fire suppression systems. A scaling procedure is introduced to avoid prohibitive exact integration of the functions obtained from Mie theory resulting in several orders in magnitude of computational savings. Spectral-based and total transmission of real spray distributions using the scaling procedure are compared to exact results and experimental data. Results show the proposed scaling procedure yields significant computational savings with little loss in accuracy for predictions of spectral and total transmission.