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Thesis (MS)--U.S. Naval Postgraduate School, 1962

Thesis (MS)--U.S. Naval Postgraduate School, 1962

Thesis (MS)--U.S. Naval Postgraduate School, 1962

A theoretical method of predicting the performance of subsonic, axial flow, multistage turbines is presented together with the digital computer program for computing all the dimensionless performance parameters required to completely define turbine performance. A small two stage turbine, for use in space vehicles, was used to demonstrate the application of the method. A complete set of performance maps were drawn and analyzed. The dimensionless performance parameters for any given flow condition could be obtained from the maps. The computer program proved to be extremely flexible and useful. The effect of blade row redesign could be easily determined. Comparison of the extremely limited amount of open cycle test data with program results showed that the method would provide a design engineer the means of predicting the performance of a given turbine design. The accuracy of such a prediction was shown to depend greatly upon the estimation of rotor tip clearances and the measurement of flow areas corresponding to the clearance. The computer program provides a means for trial and error determination of the rotor tip clearances when operating at high temperatures if accurate test data is available.

A theoretical method of predicting the performance of subsonic, axial flow, multistage turbines is presented together with the digital computer program for computing all the dimensionless performance parameters required to completely define turbine performance. A small two stage turbine, for use in space vehicles, was used to demonstrate the application of the method. A complete set of performance maps were drawn and analyzed. The dimensionless performance parameters for any given flow condition could be obtained from the maps. The computer program proved to be extremely flexible and useful. The effect of blade row redesign could be easily determined. Comparison of the extremely limited amount of open cycle test data with program results showed that the method would provide a design engineer the means of predicting the performance of a given turbine design. The accuracy of such a prediction was shown to depend greatly upon the estimation of rotor tip clearances and the measurement of flow areas corresponding to the clearance. The computer program provides a means for trial and error determination of the rotor tip clearances when operating at high temperatures if accurate test data is available.

The Image-Based Information System (IBIS) was used to automate the cross country movement (CCM) mapping model developed by the Defense Mapping Agency (DMA). Existing terrain factor overlays and a CCM map, produced by DMA for the Fort Lewis, Washington area, were digitized and reformatted into geometrically registered images. Terrain factor data from Slope, Soils, and Vegetation overlays were entered into IBIS, and were then combined utilizing IBIS-programmed equations to implement the DMA CCM model. The resulting IBIS-generated CCM map was then compared with the digitized manually produced map to test similarity. The numbers of pixels comprising each CCM region were compared between the two map images, and percent agreement between each two regional counts was computed. The mean percent agreement equalled 86.21%, with an areally weighted standard deviation of 11.11%. Calculation of Pearson's correlation coefficient yielded +9.997. In some cases, the IBIS-calculated map code differed from the DMA codes: analysis revealed that IBIS had calculated the codes correctly. These highly positive results demonstrate the power and accuracy of IBIS in automating models which synthesize a variety of thematic geographic data.

The Image-Based Information System (IBIS) was used to automate the cross country movement (CCM) mapping model developed by the Defense Mapping Agency (DMA). Existing terrain factor overlays and a CCM map, produced by DMA for the Fort Lewis, Washington area, were digitized and reformatted into geometrically registered images. Terrain factor data from Slope, Soils, and Vegetation overlays were entered into IBIS, and were then combined utilizing IBIS-programmed equations to implement the DMA CCM model. The resulting IBIS-generated CCM map was then compared with the digitized manually produced map to test similarity. The numbers of pixels comprising each CCM region were compared between the two map images, and percent agreement between each two regional counts was computed. The mean percent agreement equalled 86.21%, with an areally weighted standard deviation of 11.11%. Calculation of Pearson's correlation coefficient yielded +9.997. In some cases, the IBIS-calculated map code differed from the DMA codes: analysis revealed that IBIS had calculated the codes correctly. These highly positive results demonstrate the power and accuracy of IBIS in automating models which synthesize a variety of thematic geographic data.

Digital media are beneficial for research of complex refugee issues, as they allow refugees to express their personal experiences of complex issues in ways that are not restricted by language barriers or limited in authenticity, while also offering researchers a way to systematically compare refugees' varied experiences. We used a computerised concept mapping task to ask 74 young refugees (teenagers and young adults), from three separately recruited samples, to think about their experiences with various challenges they might face during settlement, distinguishing between their challenges in terms of size. Our analyses focused on one major challenge in Australia, learning the English language, and how it related to ten other challenges of resettlement. The three samples differed in educational setting, cultural background, age, and time in Australia. These refugees faced multiple challenges in their lives. Regardless of differences between the groups, the 74 shared a single pattern of experiences in which English language was substantially bigger, and more frequently endorsed, than other challenges. The three samples differed in how they described their experiences with their English language challenges. Our findings suggest a need for more support learning the English language, even for those who might be assumed to have good levels of conversational or academic English. This support needs to extend beyond the 510 hours of support received upon arrival in the country. Findings also suggest that such support could help young refugees overcome other challenges as they settle in Australia, especially in their academic, social, and employment experiences.