CFD models and field-measured data from large enclosed locomotive facilities

This paper compares CFD models and field-measured data from four large enclosed locomotive facilities. For each facility, CFD models were built using two computational fluid dynamics programs. These included a commercially available software package using a revised Reynolds Averaged Navier-Stokes (RANS) k-epsilon model and a public domain large eddy simulation model. This paper discusses the development of the models, compares their predictions with field measurements,
and discusses the computing times required. The field data include temperature, NOx, and CO concentration. Both CFD programs provided reasonable agreement with the fieldmeasured
data in three cases, and uncertainty in specifying the source strength for one case is discussed as the likely cause for lack of agreement in that case. Computing times for the RANS model are faster. The additional time required for the large eddy simulation model varies significantly and is dependent on the details of the problem and their influence on the grid refinement and number of time steps required.