Validation of Turbulence Models for an Automotive SCR System with Laser Doppler Anemometry Measurements Vienna University of Technology

Format:

Conference/Event

Author/Creator:

Zöchbauer, Zöchbauer, author.

Contributor:

Fischer, Simon

Harasek, Michael

Krenn, Christian

Lauer, Thomas

Pessl, Guenther

Siegmann-Hegerfeld, Tanja

Conference Name:

SAE 2013 World Congress & Exhibition (2013-04-16 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2013

Summary:

In exhaust systems with selective catalytic reduction (SCR) afast conversion of liquid urea to gaseous ammonia and a uniformdistribution of the ammonia vapor upstream of the SCR catalyst areessential to reduce the nitric oxides efficiently. For theprediction of the mixing process and the transport of ammonia vaporwith the CFD method an accurate description of the turbulent flowfield is a basic requirement.This paper presents the comparison of simulation results usingthree different turbulence models (high-Re kε-RNG model, low-Rekω-SST model, Reynolds stress model) with measurements of theturbulent velocity field using Laser Doppler Anemometry (LDA). Theinvestigations were carried out for a SCR system with a swirl mixeron a cold flow test bench for two different volume flows. From themeasured velocity signals different components of theReynolds-tensor were derived. All three turbulence models areshowing a similar mean velocity field as it was expected and thereis a good agreement with the LDA data. The turbulence intensity andsubsequently the turbulent mixing are underestimated for allsimulation setups in comparison to the LDA measurements. However,the anisotropic formulation of the turbulence intensities with theReynolds stress model (RSM) resolves the flow field more accuratelythan the two-equation turbulence models.However, further work on a more detailed formulation of theturbulent flow field (DES, LES) is necessary to improve theprediction of the turbulent species transport

Notes:

Vendor supplied data

Publisher Number:

2013-01-1579

Access Restriction:

Restricted for use by site license