Sensitivity analysis of spray painting process to input parameters: Validation of CFD jet impingement model against an experimental dataset

Abstract

Accurate modelling of the automotive spray paint process requires using Computational Fluid Dynamic (CFD) simulations built upon a number of interacting physical models. This study examines one component of the air flow in such a simulation-impinging single jet air flow and models the results in a generalizable form to allow comparison with existing practical experiment, validating the results and allowing the development of more complex models based upon reliable results. The results in this paper compare the data produced by four variations of mesh design and wall function using the k-ε model with those produced from previous practical experimental data collected in the European Research Community on Flow (ERCOFTAC) database. The CFD data for each model shows good agreement with the experimental data set in and around the boundary layer close to the jet with particularly good results using the enhanced wall treatment and a fine resolution mesh with a y+ (dimensionless wall distance) value of 1. Further refinements are required to fully resolve larger radial distances, however the general results produced show good agreement with expected phenomena.

Effect of Mixed Gas Ratio on Cooling Performance of Impinging Jets

“…If a fine mesh can be set near the wall, it is preferable to apply Enhanced Wall Treatment. However, the standard wall function was judged to be appropriate based on the mesh size of this analysis, the dimensionless parameter y+, which is an index of the turbulent boundary layer thickness 22) , and the verification results of the analysis accuracy of the thermal history. The formula for y+ is shown below.…”

Analysis of Film Forming Law and Characteristics for an Air Static Spray with a Variable Position of the Plane

“…Ye [15] adopted the Euler-Lagrange method to numerically calculate the impact process of coating droplets on the plane under the influence of two-phase flow of the air field and fog field. Barry [16] used s realizable k-ε turbulence model to simulate the impact process of a single jet on the target plane, and studied the influence of air flow rate, spraying height and other parameters on the thickness distribution of the coating during air spraying jet impact. In order to study the film forming mechanism of regular surface air spraying, Chen Yan et al used the Euler-Euler method [17,18] and the Euler-Lagrangian method [19] to study the film forming rules and characteristics of cylindrical and spherical surfaces with different sizes.…”