Browsing by Author "Palmer, Joe"

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    Modelling of cryogenic cooling system design concepts for superconducting aircraft propulsion
    (Institution of Engineering and Technology (IET), 2016-02-01) Palmer, Joe; Shehab, Essam
    Distributed propulsion concepts are promising in terms of improved fuel burn, better aerodynamic performance, and greater control. Superconducting networks are being considered for their superior power density and efficiency. This study discusses the design of cryogenic cooling systems which are essential for normal operation of superconducting materials. This research project has identified six key requirements such as maintain temperature and low weight, with two critical components that dramatically affect mass identified as the heat exchanger and compressors. Qualitatively, the most viable concept for cryocooling was found to be the reverse-Brayton cycle (RBC) for its superior reliability and flexibility. Single- and two-stage reverse-Brayton systems were modelled, highlighting that double stage concepts are preferable in specific mass and future development terms in all cases except when using liquid hydrogen as the heat sink. Finally, the component-level design space was considered with the most critical components affecting mass being identified as the reverse-Brayton compressor and turbine.
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    Quality function deployment and sensitivity analysis of requirements for future aircraft propulsion cryogenic cooling systems
    (Cranfield University Press, 2013-09-19) Palmer, Joe; Shehab, Essam; Fan, Ip-Shing; Husband, Mark
    A number of novel future airframe and propulsion concepts are considered in order to meet aviation targets set by various aviation regulatory bodies including NASA and the Advisory Council for Aeronautics Research in Europe (ACARE). The current NASA concept for long-range civil aircraft is the Blended-Wing Body (BWB) aircraft, coupled with turbo-electric distributed propulsion (TeDP), to enable a host of efficiency benefits over current designs. NASA has identified superconducting technology as a key enabler to deliver this airframe. Superconductors need to be cooled to cryogenic temperatures for normal operation. Using a sensitivity matrix, it was found that the Exchange Heat and Transport/Pump Cryogen functions are the most sensitive to input variation. The failure modes and effects analysis performed on the functional model show that the detection functions are critical during component failure. Quality Function Deployment (QFD) analysis shows the Exchange Heat and Transport/Pump Cryogen functions are also critical.