The impact of the surface macro-roughness on the surface shear stress and rate under the oblique linear cylindrical nozzle jet as pertinent to particles detachment

• Novel cylindrical linear oblique jet was investigated numerically.
• Published experimental data of the impinging jets were modelled with good fidelity.
• Wall shear stress and rate at the wall were obtained.
• Multi-fold difference between leeward and forward maximal shear was shown.
• Very strong impact of the macro-roughness on those values was demonstrated.

Particles mitigation and decontamination by impinging jets is commonly used in various engineering in both indoor and outdoor settings. The current research is concerned with advancing the understanding of the phenomena occurring under the specific linear cylindrical nozzle, as well as under the oblique linear nozzle in general. The numerical method is extensively validated using published experimental data before being applied to the configuration of interest. The results demonstrate large differences between the forward and leeward maximal shear stress and rate at the surface impacted by the oblique jet and the impact of the macro-roughness on their values.