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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.

The tailpipe noise from an aftertreatment system must comply with legislation and meet customer expectations. The approach to capture the influence of complicated geometries and the ceramic substrates included in full aftertreatment systems (ATS) is implemented by coupling the 1D analytical solution of the substrates with the 3D FEM solution. The simulations are verified with measurements in a flow acoustic test rig.

Exhaust noise must comply with legislation requirements and meet customer expectations and cost reduction, which call for design optimisation of the exhaust systems in the development process. One solution is to calculate the transfer matrix of the silencer using 3D linear pressure acoustics in a FEM software. The transfer matrix is the basis for calculating either the insertion loss or transmission loss of a silencer. The simulations of different silencer configurations are verified with measurements in a flow acoustic test rig using the two source method, and this test setup is, without modifications, also used for extracting the complex wave number and impedance of isotropic absorptive material, which are used to update the FE models.