Steady inspiratory and expiratory flow in a symmetrically bifurcating airway model was studied numerically using the finite element method (FIDAP). Flows of Reynolds number of 500 and 1000 during inspiration and a flow of Reynolds number of 500 during expiration were analyzed. Since the geometry of the bifurcation model used in this study is exactly the same as the model used in the experimental studies, the computed results were compared to the experimental findings. Results show that most of the important flow features that were observed in the experiment, such as the skewed velocity profiles in the daughter branches during inspiration and velocity peak in the parent tube during expiration, were captured in the numerical simulation. Quantitatively, the computed velocity profiles are in good agreement with the measured profiles. This comparison validates the computational simulations.
This study addresses the problem of fitting anthropometric data from different populations to proportional man models. Proportional models simulate the human shape by assuming fixed proportions between the various body dimensions. Percentiles can be created in such a model but are constrained by the given body proportions. Prime Computer's SAMMIE man model is an example of the proportional approach. The SAMMIE model is described with reference to the anatomical features it simulates. The constraints imposed by a proportional model are discussed. These include Ink lengths, flesh envelope and ranges of joint motion. A linear programming methodology is presented to fit available population data to the model. This program is designed with a user friendly graphic interface allowing the designer to easily of principle interest. A validation study of the method using NASA data is reported.
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