Norbert Mueller | Michigan State University (original) (raw)

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Papers by Norbert Mueller

Journal of Advanced Materials, 2010

Http Dx Doi Org 10 1080 13647830 2014 894643, Mar 4, 2014

The accuracy of the Content should not be relied upon and should be independently verified with p... more The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden.

Proceedings of CIMAC Congress. Kyoto, 2004

A thermodynamic cycle analysis is performed to compare the performance improvement of simple cycl... more A thermodynamic cycle analysis is performed to compare the performance improvement of simple cycle (unrecuperated) and recuperated microturbines using a four-port wave rotor. Based on possible design restrictions and preferences, two advantageous implementation cases are considered for the wave rotor into given baseline engines. Advantages and disadvantages are outlined. Comparison of the theoretical performance parameters shows that the greatest performance gain for the topped engine without recuperation is obtained if the topped engine operates with the same turbine inlet temperature and compressor pressure ratio as the baseline engine. For the recuperated engine, however, the case in which the topping cycle operates with the same turbine inlet temperature and same overall pressure ratio as the baseline engine results in the highest performance enhancement. Both simple cycle and recuperated engines benefit from the wave-rotor-topping, but the performance improvement is greater for the simple engine without recuperation.

Abstract: In the hostile and highly corrosive marine environment, advanced composite materials ca... more Abstract: In the hostile and highly corrosive marine environment, advanced composite materials can be used in marine current turbines due to their high strength-to-weight ratios and excellent resistance to corrosion. A composite material marine current turbine (CMMCT), which has significant advantages over traditional designs, has been developed and investigated numerically. A substantial improvement in turbine performance is achieved by placement of a duct to concentrate the energy. Computational fluid dynamics results ...

Combustion Theory and Modelling, 2014

This article examines the detailed combustion process in a theoretical model with applicability t... more This article examines the detailed combustion process in a theoretical model with applicability to combustion in a wave rotor or wave disc engine. The model comprises a single channel into which an initial loading of methane and air is admitted and ignited after all inlet and exit ports have been closed. Combustion takes place at constant volume. However, the initial gaseous mixture in the channel is not at rest. The initial opening and closing of the ports generates significant vorticity which influences the evolution of the combustion process. Numerical evaluations are provided for the detailed flame shape for simplified (one-step) chemistry and a simulation using the detailed 235-step San Diego scheme. Quantities examined are the evolution of vorticity, pressure fluctuations, mass consumption rate, flame surface area and the influences on combustion of adiabatic and non-adiabatic channel walls. Combustion regimes are identified and compared with simpler model studies (no initial flow). Pointwise quantities are examined to describe the various stages of burning in the channel. The focus of the study is directed towards quantities that influence overall burning rate and completeness of combustion.

Materials & Design, 2011

a b s t r a c t Centrifugal forces are generated by a spinning impeller, of magnitudes that creat... more a b s t r a c t Centrifugal forces are generated by a spinning impeller, of magnitudes that create large stresses. Aerodynamic forces are also imparted on an impeller blade, which varies with time and position. These two forces play different roles during compressor events. Damage accumulated from these events results in the fatigue failure of impeller material and structure. Therefore, it is important to design an impeller against dynamic and fatigue failure. The finite element method has been used in the study of impeller fracture mechanics and is regarded as an important tool in the design and analysis of material and structures.

48th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, 2012

44th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, 2008

Various needs exist for small-scale power generation in consumer and military applications, but e... more Various needs exist for small-scale power generation in consumer and military applications, but energy conversion efficiency is notoriously poor at small scales. Conventional engine architectures of gas turbine and piston engines suffer from excessive friction, leakage, and heat losses ...

4th International Energy Conversion Engineering Conference and Exhibit (IECEC), 2006

Journal of Engineering for Gas Turbines and Power-transactions of The Asme - J ENG GAS TURB POWER-T ASME, 2006

The objective of this paper is to provide a succinct review of past and current research in devel... more The objective of this paper is to provide a succinct review of past and current research in developing wave rotor technology. This technology has shown unique capabilities to enhance the performance and operating characteristics of a variety of engines and machinery utilizing thermodynamic cycles. Although there have been a variety of applications in the past, this technology is not yet widely used and is barely known to engineers. Here, an attempt is made to summarize both the previously reported work in the literature and ongoing efforts around the world. The paper covers a wide range of wave rotor applications including the early attempts to use wave rotors, its successful commercialization as superchargers for car engines, research on gas turbine topping, and other developments. The review also pays close attention to more recent efforts: utilization of such devices in pressure-gain combustors, ultra-micro gas turbines, and water refrigeration systems, highlighting possible further efforts on this topic. Observations and lessons learnt from experimental studies, numerical simulations, analytical approaches, and other design and analysis tools are presented. Fig. 26 Historical perspective of wave rotor technology. Red: gas turbine application. Green: IC engine supercharging. Blue: refrigeration cycle. Pink: pressure divider and equalizer. Purple: wave superheater. Orange: internal combustion wave rotors. Black: general applications.

41st AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, 2005

... a compressor pressure ratio of 3.6, the plot predicts an attractive relative performance impr... more ... a compressor pressure ratio of 3.6, the plot predicts an attractive relative performance improvement in thermal ... As a result, utilizing wave rotor technology to improve the performance of UµGT has ... The large size is due to the use of two centrifugal compressors with comparably ...