Although there is abundant literature for both experimental and numerical studies of respiratory aerosol exposure in nasal airways, research efforts concentrating on diseased nasal cavities undergoing pathological changes remain significantly less. This paper presents a comparative study of pre- and post-operative nasal airway models based on a 3-year-old nasal cavity model with severe nasopharynx obstruction due to the presence of adenoid hypertrophy. By numerically comparing the airflow dynamics and nanoparticle deposition characteristics in original diseased and post-operative healthy nasal airway models, our results demonstrated that nasopharynx obstruction can induce significantly biased flow distribution in the main nasal passage, despite the obstruction site is located downstream of the nasal airway. In addition, the regional particle deposition analysis revealed that the affected area can receive better nanoparticle aerosol delivery after receiving surgical treatment (adenoidectomy) due to restored normal flow fields. More importantly, ventilation and particle deposition improvements were achieved for the olfactory region in the post-operative nasal model, which indicates a more promising olfactory drug delivery using nanoparticles. Research findings are expected to provide scientific evidence for adenoidectomy planning and intranasal aerosol therapy, which can substantially improve present clinical treatment outcomes.

As one of the most basic parameters, manikin body feature could be an important factor influencing the airflow and temperature fields in indoor environments. This study aims to improve the computational efficiency by optimising and simplifying manikin body features. A 3D scanned computer-simulated person (CSP) with extremely detailed body features was employed, followed by two simplified CSP models with different approaches. One of the simplified models was rebuilt based on the skeleton of the 3D scanned model with very limited body features, while the other model was simplified by removing some of the features from the 3D scanned model. All CSPs were tested under quiescent condition, followed by further comparisons under displacement and mixed ventilations. The outcomes indicated that the geometric difference of manikin body would have significant impact on the airflow patterns near manikin bodies, whilst it has very limited influence on the temperature field. The difference of body features could significantly affect the development of thermal plume, which mainly reflected above the manikin head. Also, change of CSP body features due to simplifications may become more sensitive to the predicted results under mixed ventilation, as a result of fewer interactions between the thermal plume and injected airflow.

The relative freshness of indoor air in breathing zone can be measured by ventilation effectiveness. Numerous research articles in literature have investigated ventilation effectiveness under different ventilation schemes, different inlet/outlet positions, and different diffusor types. These researches seem to have a goal to find a solution to optimize ventilation effectiveness through manipulating ventilation system. In reality, however, the occupants of a rented office room have no right to manipulate the ventilation system; instead, they have to accept whatever rented to them. An important issue thus arises: how to improve ventilation effectiveness without changing ventilation system? This paper has built a CFD model about a typical office room, validated it by published experimental data in literature, and then applied it to twelve typical office situations/cases of different furniture layouts under different ventilation schemes. The simulation results of twelve cases show that furniture layout is an important factor in indoor airflow and temperature fields, and the quality of air in breathing zone can be significantly improved by adjusting furniture layout without making any change in ventilation system.