This paper details the numerical analysis of different vaned and vaneless radial inflow turbine stators. Selected results are presented from a test program carried out to determine performance differences between the radial turbines with vaned stators and vaneless volutes under the same operating conditions. A commercial computational fluid dynamics code was used to develop numerical models of each of the turbine configurations, which were validated using the experimental results. From the numerical models, areas of loss generation in the different stators were identified and compared, and the stator losses were quantified. Predictions showed the vaneless turbine stators to incur lower losses than the corresponding vaned stator at matching operating conditions, in line with the trends in measured performance. Flow conditions at rotor inlet were studied and validated with internal static pressure measurements so as to judge the levels of circumferential nonuniformity for each stator design. In each case, the vaneless volutes were found to deliver a higher level of uniformity in the rotor inlet pressure field.

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current treatments and assists in the interpretation of treatment failures.Methods: One hundred twenty-eight cadaveric tissue blocks containing the pterygopalatine fossae were used. One hundred eighteen blocks were dissected using a Watson-Barnet 25ϫ dissecting microscope. Ten blocks were cleared by the Spalteholz technique after injection with latex-Indian Ink. Arterial configurations were analyzed and photographic records were made.Results: Analysis of the arteries in the pterygopalatine fossa showed 3 common configurations: a single looped form (18%) and 2 double-looped forms (51% and 31%). Terminal bifurcation of the sphenopalatine artery arose before the sphenopalatine foramen in 74.6%. In contrast to previous smaller studies, we found remarkable symmetry in the size of the maxillary arteries and a low incidence of "early" pharyngeal arteries.Conclusion: This is the most comprehensive anatomical study of the distal maxillary artery. The arterial configuration can be easily classified into 3 common forms. Some forms are more liable to lead to confusion at the time of ligation particularly if the osteotomy is inadequate.Significance: Understanding of the arterial anatomy and its variants will reduce the risk of technical failures and improve both the rationale and the reliability of ligation procedures in the treatment of epistaxis.

The airflow simulations indicate that the inferior and middle turbinates and Little's area on the anterior nasal septum contribute significantly to nasal air-conditioning. The concentration of wall shear stress within Little's area indicates a desiccating and potentially traumatic effect of inhaled air that may explain the predilection for spontaneous epistaxis at this site.

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