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Andrew Naples

Bio: Andrew Naples is an academic researcher from Ohio State University. The author has contributed to research in topics: Detonation & Deflagration to detonation transition. The author has an hindex of 12, co-authored 25 publications receiving 779 citations.

Papers
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Journal ArticleDOI
TL;DR: In this article, the detonations propagating through the annular channel of an optically accessible rotating detonation engine (RDE) operating on hydrogen-air are visualized using OH* chemiluminescence imaging.

274 citations

Journal ArticleDOI
TL;DR: In this article, rotating detonation engines are compared to pulsed detonation engine and they are shown to produce thrust with fuel efficiencies similar to those associated with pulsed engines while operating on gaseous hydrocarbon fuels.
Abstract: Recent accomplishments related to the performance, application, and analysis of rotating detonation engine technologies are discussed. The pioneering development of optically accessible rotating detonation engines coupled with the application of established diagnostic techniques is enabling a new research direction. In particular, OH* chemiluminescence images of detonations propagating through the annular channel of a rotating detonation engine are reported and appear remarkably similar to computational fluid dynamic results of rotating detonation engines published in the literature. Specific impulse measurements of rotating detonation engines and pulsed detonation engines are shown to be quantitatively similar for engines operating on hydrogen/air and ethylene/air mixtures. The encouraging results indicate that rotating detonation engines are capable of producing thrust with fuel efficiencies that are similar to those associated with pulsed detonation engines while operating on gaseous hydrocarbon fuels....

157 citations

Proceedings ArticleDOI
05 Jan 2015
TL;DR: In this paper, the authors visualized the detonation propagating through the annular channel of an optically accessible non-premixed rotating detonation engine (RDE) using OH* chemiluminescence imaging.
Abstract: The detonation propagating through the annular channel of an optically accessible nonpremixed rotating detonation engine (RDE) is visualized in this work using OH* chemiluminescence imaging. The fuel and air are injected from separate streams and partially premix in the channel in front of the detonation wave. The OH* chemiluminescence images allow observation of the size and shape of the detonation structure, trailing edge oblique shock wave, and possible presence of deflagration between the fuel fill region and expansion region containing detonated products. The OH* chemiluminescence images are useful for evaluating the effects of the air mass flow rate, equivalence ratio, air injection area, and fuel injection scheme on the detonation structure and its corresponding impact on RDE operation and performance. The detonation increases in height as the air mass flow rate is increased for low flow rates, experiences subtle changes in size and shape for intermediate flow rates, and transitions from one-wave to two-waves as the flow rate is further increased. For fuel lean conditions, the high OH* emissions from the detonation are distributed more broadly in space. For stoichiometric and fuel rich conditions, the high OH* emissions typically are confined to a more narrow region near the detonation wave front. The wave front is more concave with respect to the fuel fill region in front of the detonation as the air injection slot is increased from low to intermediate values. The angle between the wave front and fuel injection surface in front of the detonation becomes more acute as the air injection slot is further increased. Reducing the number of fuel injection holes has significant effects on the detonation structure including transition from one-wave to two-waves. The waves typically co-rotate with the detonations propagating in the same azimuthal direction for most conditions in which two-waves are established in the channel. Counter-rotating waves with the detonations propagating in the opposite azimuthal direction are observed for some conditions. The observation of two counter-rotating detonation waves demonstrates one occasional effect of non-ideal mixing between the fuel and air in a nonpremixed RDE. The OH* chemiluminescence images are useful for evaluating RDE models and simulations, improving fundamental understanding of the detonation structure in nonpremixed RDEs, and identifying critical design parameters that influence RDE operation and performance.

91 citations

Proceedings ArticleDOI
07 Jan 2013
TL;DR: A rotating detonation engine (RDE) at the Air Force Research Lab (AFRL) has been modified to allow optical access to the annulus while in operation.
Abstract: A rotating detonation engine (RDE) at the Air Force Research Lab (AFRL) has been modified to allow optical access to the annulus while in operation. High speed video of chemiluminescence was taken for three operating conditions to characterize the RDE flowfield. Two-dimensional representations of the entire RDE are presented to show basic flow structure. Detonation height, detonation angle, oblique shock wave angle, shear layer angle, and contact surface angle were measured. Average value for each of these measurements did not change drastically over the range tested, but large deviations of the values were observed. These considerable deviations of the flowfield point toward device variation as a major factor to be understood.

69 citations

Proceedings ArticleDOI
09 Jan 2012
TL;DR: A Rotating Detonation Engine engineered and manufactured by Pratt and Whitney Seattle Aerosciences Center was loaned to the Air Force Research Laboratory at WrightPatterson Air Force Base for further testing and development.
Abstract: A Rotating Detonation Engine engineered and manufactured by Pratt and Whitney Seattle Aerosciences Center was loaned to the Air Force Research Laboratory at WrightPatterson Air Force Base for further testing and development. The engine was originally designed for ethylene and oxygen, but was altered in order to use hydrogen and air. The engine was tested at a wide range of flow rates and equivalence ratios with hydrogen-air in order to obtain a matrix of the operating space. Although a considerable portion of the test matrix contained successful detonations, all of the detonations that occurred for the tested configuration were in the fuel rich operating regime. In the pursuit of greater thrust output and a wider range of operability, the air was slightly enriched with additional oxygen. The addition of extra oxygen not only increased the range of thrust output and operability, it also allowed the engine to detonate at high enough air mass flows that two detonation waves were established in the engine. The detonation wave activity during the approach and through the transition from one detonation wave to two detonation waves was analyzed in order to gain a deeper understanding of the transition phenomenon.

67 citations


Cited by
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Journal ArticleDOI
TL;DR: In this paper, an assessment of the challenges of understanding basic physics through utilizing rotating detonations in aerospace platforms is provided, ranging from understanding the basic physics of the system to its feasibility.
Abstract: Rotating detonation engines (RDEs), also known as continuous detonation engines, have gained much worldwide interest lately. Such engines have huge potential benefits arising from their simplicity of design and manufacture, lack of moving parts, high thermodynamic efficiency and high rate of energy conversion that may be even more superior than pulse detonation engines, themselves the subject of great interest. However, due to the novelty of the concept, substantial work remains to demonstrate feasibility and bring the RDE to reality. An assessment of the challenges, ranging from understanding basic physics through utilizing rotating detonations in aerospace platforms, is provided.

451 citations

Journal ArticleDOI
TL;DR: A review of the development, application, and current capabilities of infrared laser-absorption spectroscopy (IR-LAS) sensors for combustion gases can be found in this paper.

438 citations

Journal ArticleDOI
TL;DR: In this article, the detonations propagating through the annular channel of an optically accessible rotating detonation engine (RDE) operating on hydrogen-air are visualized using OH* chemiluminescence imaging.

274 citations

Journal ArticleDOI
TL;DR: An overview of the research done worldwide to address some of the challenges and questions pertaining to the physics of rotating detonation combustors operation is provided in this paper, where notable parallels are drawn to the phenomena of low and high frequency instabilities in solid and liquid rockets that have been recognized as the most severe hindrance to their operation.

204 citations

Journal ArticleDOI
TL;DR: In this article, a large-scale continuous detonation combustor (CDC) has been designed, fabricated and tested to study the effect of different design elements on the operation process and CDC propulsion performance.

198 citations