Validation of a CFD Spray Model Based on Spray Nozzle Characteristics

The purpose of this work is to determine essential spray parameters for a specific nozzle to be integrated in computational fluid dynamics (CFD) simulations of selective catalytic reduction systems (SCR) based on the injection of urea water solution (UWS). As Dinex does not develop nozzles, but rather integrate nozzles from a variety of manufacturers, the spray data made available is of an inhomogeneous quality. This paper presents the results of a simple, partial validation and calibration of a CFD simulation performed with the commercial CFD code AVL FIRE 2014.2 using the Lagrangian discrete droplet method. The validation is based on a novel and low cost experimental setup, where the experimental method utilizes high-speed imaging to provide spray cone angle, axial spray penetration length and spray plume droplet density. A description of the post-processing of experimental data is also provided, including a method to automatically evaluate spray cone angle using the Hough-transform.