Free-piston Stirling engine conceptual design and technologies for space power, phase 1

As part of the SP-100 program, a phase 1 effort to design a free-piston Stirling engine (FPSE) for a space dynamic power conversion system was completed. SP-100 is a combined DOD/DOE/NASA program to develop nuclear power for space. This work was completed in the initial phases of the SP-100 program prior to the power conversion concept selection for the Ground Engineering System (GES). Stirling engine technology development as a growth option for SP-100 is continuing after this phase 1 effort. Following a review of various engine concepts, a single-cylinder engine with a linear alternator was selected for the remainder of the study. The relationships of specific mass and efficiency versus temperature ratio were determined for a power output of 25 kWe. This parametric study was done for a temperature ratio range of 1.5 to 2.0 and for hot-end temperatures of 875 K and 1075 K. A conceptual design of a 1080 K FPSE with a linear alternator producing 25 kWe output was completed. This was a single-cylinder engine designed for a 62,000 hour life and a temperature ratio of 2.0. The heat transport systems were pumped liquid-metal loops on both the hot and cold ends. These specifications were selected to match the SP-100 power system designs that were being evaluated at that time. The hot end of the engine used both refractory and superalloy materials; the hot-end pressure vessel featured an insulated design that allowed use of the superalloy material. The design was supported by the hardware demonstration of two of the component concepts - the hydrodynamic gas bearing for the displacer and the dynamic balance system. The hydrodynamic gas bearing was demonstrated on a test rig. The dynamic balance system was tested on the 1 kW RE-1000 engine at NASA Lewis

Performance characteristics of several divergent-shroud aircraft ejectors

Performance characteristics of several divergent- shroud aircraft ejector

Internal performance characteristics of short convergent-divergent exhaust nozzles designed by the method of characteristics

Internal performance data on a short exhaust nozzle designed by the method of characteristics were obtained over a range of pressure ratios from 1.5 to 22. The peak thrust coefficient was not affected by a shortened divergent section, but it occurred at lower pressure ratios due to reduction in expansion ratio. This nozzle contour based on characteristics solution gave higher thrust coefficients than a conical convergent-divergent nozzle of equivalent length. Abrupt-inlet sections permitted a reduction in nozzle length without a thrust-coefficient reduction

A study of oxygen diffusion through frozen food packaging materials

Call number: LD2668 .T4 1951 B43Master of Scienc

A Cause to Action: Learning to Develop a Culturally Responsive/Relevant Approach to 21st Century Water Safety Messaging through Collaborative Partnerships

Globally, and in the United States, drowning is considered a “neglected public health threat” (WHO, 2014b). Reports have shown that there are groups of people in certain communities who are at greater risk. African Americans, as a group, have a drowning death rate 9% higher than that of the overall population, with the greatest disparity being among African American youth (Gilchrist & Parker, 2014). While many national programs and organizations present water safety awareness and drowning prevention efforts within communities, very few offer multi-sectorial collaborative efforts (WHO, 2017a) among culturally and linguistically diverse (CLD) aquatic stakeholders designed to empower, promote, and support water safety awareness in communities. Inspired by evidence-based research, derived from a national water safety and drowning prevention campaign, the purpose of this article is to answer a call to action by the World Health Organization (2017a) to approach water safety education through a social justice lens to inform programming and collaborative partnerships