Cornell AUVSI Competition Entry 2005
This paper presents the 2005 Autonomous Underwater Vehicle (AUV) designed by the Cornell University AUV Team. This year's vehicle builds on the team's previous iterations and maintains the aspects that have proven to be successful in the past, including a dual hull structure, brushless motors, explicit separation of hardware by functionality, and flexible software. Significant improvements made this year include a modular sensor infrastructure, signal and power backplanes, enhanced power management, and improved vehicle control.
Modular hardware infrastructure for autonomous underwater vehicles
Autonomous underwater vehicles (AUVs) are taking on increasingly visible and valuable roles in oceanographic research institutions, the offshore industry, and the military (Podder et al., 2004 and Yongkuan, 2002). AUV research, especially at the university level, is hindered by the lack of flexible and affordable platforms suitable for a wide range of applications. This paper presents an electrical and mechanical infrastructure developed to improve the flexibility and modularity of research AUVs. External devices can be added or replaced with minimal vehicle modification. A power backplane offers built-in monitoring and switching for all electronic devices. A signal backplane allows new electronics to be quickly integrated into the existing system. Easily detachable segments make the entire system mechanically modular.
Evaluation of CuAl2O4 as an Oxygen Carrier in Chemical-Looping Combustion
The chemical-looping combustion (CLC) process is a novel solution for efficient combustion with intrinsic separation of carbon dioxide. The process uses a metal oxide as an oxygen carrier to transfer oxygen from an air to a fuel reactor where the fuel, or gasification products of the fuel, reacts with the solid oxygen carrier. In this work, copper(II) aluminate (CuAl2O4) was assessed as a potential oxygen carrier using methane as fuel. The carrier particles were produced by freeze–granulation and calcined at 1050 °C for a duration of 6 h. The chemical-looping characteristics were evaluated in a laboratory-scale fluidized-bed reactor in the temperature range of 900–950 °C during 45 alternating redox cycles. The oxygen carrier exhibited reproducible and stable reactivity behavior in this temperature range. Neither agglomeration nor defluidization was noticed in any of the cycles carried out at 900–925 °C. However, after reactivity tests at 950 °C, soft agglomeration and particle fragmentation were observed. Systematic phase analysis of the Cu–Al–O system during the redox cycle was carried out as a function of duration of reduction and oxygen concentration during the oxidation period. It was found that the CuAl2O4 is reduced to copper(I) aluminate (CuAlO2; delafossite), Cu2O, and elemental Cu. The CuAlO2 phase is characterized by slow kinetics for oxidation into CuO and CuAl2O4. Despite this kinetic limitation, complete conversion of methane with reproducible reactivity of the oxygen carrier is achieved. Thus, CuAl2O4 could be a potential oxygen carrier for chemical-looping combustion.