It's important to understand that a Computational Fluid Dynamics analysis of any bridge cross-section requires some model parameters calibration and it's applicable only to earlier phases of the design process as it also needs a later definitive verification with Wind Tunnel tests in the final design or at the construction stages.
RM Bridge CFD module defines a starting point for the parameters to be used with the Aero Classes for calculating an estimation of the Steady State Coefficients; though, these starting values automatically suggested by the program might not be the best possible option for the model in the study. Therefore, we recommend to our users for creating a parallel analysis and be as critical as possible of the results.
This parametric calibration can be performed by analyzing the starting values with a variable factor, from 0.1 to 2 by a constant increment of 0.1. This can be applied to:
The results are then compared for the forces of Drag, Lift, and Moments. As shown in the image below, plotting them is very useful to identify numerical issues like local peaks and divergences or convergences.
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New parameters can be established and new results can be considered final for the preliminary stages of analysis.