Exploring the relationship between particle deposition and near-wall turbulence quantities in the built environment

Abstract

Particle deposition in the built environment can cause discoloration or damage to indoor surfaces. To better understand the deposition mechanisms, this study explored the relationship between particle deposition and near-wall turbulence quantities by means of experimental measurements and numerical simulations, taking a multi-slot supply air nozzle in a commercial airplane as an example. Chamber experiments were conducted in a cabin mockup to measure the particle deposition velocity distribution on the multi-slot nozzle and the near-wall 3D air velocity components. The large-eddy simulation (LES)-Lagrangian approach was used to calculate the turbulent flow in the cabin and particle deposition on the nozzle. Correlations between the particle deposition velocity (vd) and the wall-normal turbulence kinetic energy (kw), the wall-normal turbulence intensity (TIw), and a new turbulence quantity defined in this study (TIw,towards−wall) were examined in the near-wall buffer, logarithmic, and outer layers. According to the simulation results, the particle deposition velocity was significantly correlated with all three turbulence quantities (TIw, kw, TIw,towards−wall) in the logarithmic and outer layers. Furthermore, both the experimental and simulation results indicate that the new turbulence quantity defined in this study (TIw,towards−wall) was most closely correlated with the particle deposition velocity (vd) among the three near-wall quantities.