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Performance when gliding in the streamlined position depends on a swimmer’s morphological characteristics, body orientation and water characteristics. The purpose of this thesis was twofold. First to identify and assess the effect of controllable factors that contribute to glide performance and second to form the foundations of an improved approach of simulating the fluid flow around the swimmers’ body. To address the purposes of the thesis four investigations were conducted. Study 1. The effect of the head position on glide performance was investigated. When the high, medium and low head positions were compared, it was found that swimmers experience significantly greater resistance and decelerate faster when they adopt a high head position. It was also found that there is no significant difference between the medium and low head position indicating for the first time that swimmers can choose any of the positions according to their natural tendency. Study 2. The second study examined the effect of gliding depth on gliding performance. A range of depths was investigated ranging from 0.8 m to 0.2 m from the water surface. The results demonstrated significantly higher glide factor values for glides at a greater depth when compared to glides closer to the water surface highlighting the retarding effect of wave drag when gliding close to the surface. The optimum gliding performance was reported for glides at 0.8 m from the surface. Study 3. The third study investigated the effect of full body swimsuits on glide performance. According to the findings, it is demonstrated for the first time that the improved gliding performance when wearing full body swimsuits is linked to changes in swimmers’ morphology due to compression. Study 4. In the fourth study the magnitude of resistive forces applied on a swimmer’s body when gliding underwater was assessed with the use of computational fluid dynamics (CFD) and the LES approach. The results showed a close match between the glide factor values of the experimental and the computational findings demonstrating the effectiveness of the CFD method when the LES approach is employed.

Predicting vapor transport and aerosol dynamics in the respiratory airways is important for analyzing both environmental exposure and respiratory drug delivery. A large number of analytical models, computational studies, and experiments on vapor and aerosol transport in the respiratory tract have been conducted previously. However, a number of critical questions remain unanswered. In this study, computational fluid dynamics (CFD) is primarily employed with frequent comparisons to existing and new experimental data sets to address previously unanswered issues related to the transport of vapors and aerosol in the respiratory tract. The three objectives of this study are further described below. Objective 1: A CFD model was developed to predict the transient absorption of inhaled vapors in the respiratory tract. Results indicated that transient absorption can significantly influence the transport and uptake of vapors in the walls of the conducting airways. Objective 2: The concept of enhanced condensational growth (ECG) applied to respiratory drug delivery was tested in a representative airway model extending from the oral cavity to the end of the tracheobronchial (TB) airways. Results indicated that ECG is an effective method to provide near full lung retention of the aerosol. The CFD results also indicated that the ECG delivery approach under transient inhalation conditions increased aerosol deposition in the TB airways by only a small amount, as compared with steady state conditions. Objective 3: The effect of transient waveforms on the transport and deposition of pharmaceutical aerosols from inhalers in the upper airways was considered. Results indicated that the CFD model predictions matched the in vitro experiments to a high degree. The CFD results also indicated that it was critical to consider transient inhalation effects when assessing aerosol deposition. The stochastic individual path (SIP) modeling approach was then introduced and implemented to evaluate the transport and deposition of pharmaceutical aerosols from inhalers in medium and small TB airways. Results indicated that steady state inhalation could be used to predict deposition efficiencies in the TB airways between the 4th branch (B4) and the bronchioles (B15).