Cross-Plane Particle Concentration Measurements in a Simulated Atmospheric Turbulent Boundary Layer

We experimentally investigate turbulent particle dispersion in a neutral atmospheric boundary layer, with specific focus on ship exhaust plumes. The atmospheric boundary layer is simulated in a wind tunnel using a Counihan spire and barrier system. Particle concentration fields are obtained through an optical-based counting method calibrated with a particle counter. A scaled cruise ship model is tested at yaw angles of 0°, 45°, and 90° relative to the incoming wind. The results are compared with analytical solutions for point-source dispersion, including the classical point source in uniform-flow formulation and an extended solution for a point source in a boundary layer, obtained through a combination of analytical and numerical methods. Additional far-downstream measurements have been carried out to examine the generality of dispersion behavior.