Abstract
Geometric modification of ultraviolet (UV) reactors enhances radiation distribution and disinfection efficiency, although it may increase hydraulic resistance. In this study, a numerical and statistical approach was adopted to improve the parameters of a corrugated UV reactor, aiming to maximize the mean cumulative UV dose while quantifying the associated pressure-loss penalty. Thirteen simulation cases were defined using experimental design to inspect the effects of three geometric parameters: inward radial depth (a), axial groove length (b), and axial ridge length (c). A quadratic response surface model was developed to describe the relationship between the geometric parameters and the response. The model provided a strong in-sample fit to the simulated responses; nevertheless, its predictive reliability should be further assessed using independent simulations or experiments. Across the 13 DOE cases, the mean cumulative UV dose ranged from 38.927 to 51.366 mJ/cm2, corresponding to a 31.95% increase from the minimum to the maximum observed value. The pressure loss ratio varied from 1.000 to 1.172, implying a maximum hydraulic increase of 17.2%. The quadratic RSM predicted an interior stationary point at the coded factor levels a=1.391, b=1.872, and c=2.572, corresponding to the real geometric dimensions A=9.740 mm, B=56.170 mm, and C=77.169 mm, with a predicted mean cumulative UV dose of 52.467 mJ/cm2; this point remained distinct from the 13 simulated DOE cases. The concave response surface indicated a stationary maximum rather than a boundary-driven solution.