OH* Chemiluminescence Imaging of the Combustion Products From a Methane-Fueled Rotating Detonation Engine

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Jonathan Tobias ◽  
Daniel Depperschmidt ◽  
Cooper Welch ◽  
Robert Miller ◽  
Mruthunjaya Uddi ◽  
...  
Keyword(s):  
Power Generation ◽  
Gas Turbines ◽  
Combustion Products ◽  
Combined Cycle ◽  
Oblique Shock Wave ◽  
Rotating Detonation Engine ◽  
Continuous Detonation ◽  
Detonation Engine ◽  
Rotating Detonation ◽  
Probe Measurements

Pressure gain combustion (PGC) has been conceived to convert fuel's chemical energy into thermal energy and mechanical energy, thereby reducing the entropy production in the process. Recent research has shown that the rotating detonation combustor (RDC) can provide excellent specific thrust, specific impulse, and pressure gain within a small volume through rapid energy release by continuous detonation in the circumferential direction. The RDC as a PGC system for power generating gas turbines in combined cycle power plants could provide significant efficiency gains. However, few past studies have employed fuels that are relevant to power generation turbines, since RDC research has focused mainly on propulsion applications. In this study, we present experimental results from RDC operated on methane and oxygen-enriched air to represent reactants used in land-based power generation. The RDC is operated at a high pressure by placing a back-pressure plate downstream of the annular combustor. Past studies have focused mainly on probe measurements inside the combustor, and thus, little information is known about the nature of the products exiting the RDC. In particular, it is unknown if chemical reactions persist outside the RDC annulus, especially if methane is used as the fuel. In this study, we apply two time-resolved optical techniques to simultaneously image the RDC products at framing rate of 30 kHz: (1) direct visual-imaging to identify the overall size and extent of the plume, and (2) OH* chemiluminescence imaging to detect the reaction zones if any. Results show dynamic features of the combustion products that are consistent with the probe measurements inside the rotating detonation engine (RDE). Moreover, presence of OH* in the products suggests that the oblique shock wave and reactions persist downstream of the detonation zone in the RDC.

OH* Chemiluminescence Imaging of the Combustion Products From a Methane-Fueled Rotating Detonation Engine

2018 ◽  
Author(s):  
J. Tobias ◽  
D. Depperschmidt ◽  
C. Welch ◽  
R. Miller ◽  
M. Uddi ◽  
...  
Keyword(s):  
Power Generation ◽  
Gas Turbines ◽  
Power Plants ◽  
Mechanical Energy ◽  
Combustion Products ◽  
Combined Cycle ◽  
Oblique Shock Wave ◽  
Continuous Detonation ◽  
Rotating Detonation ◽  
Probe Measurements

Pressure gain combustion (PGC) has been conceived to convert fuel’s chemical energy into thermal energy and mechanical energy, thereby reducing the entropy production in the process. Recent research has shown that the rotating detonation combustion or combustor (RDC) can provide excellent specific thrust, specific impulse, and pressure gain within a small volume through rapid energy release by continuous detonation in the circumferential direction. The RDC as a PGC system for power generating gas turbines in combined cycle power plants could provide significant efficiency gains. However, few past studies have employed fuels that are relevant to power generation turbines, since RDC research has focused mainly on propulsion applications. In this study, we present experimental results from RDC operated on methane and oxygen-enriched air to represent reactants used in land-based power generation. The RDC is operated at a high pressure by placing a back-pressure plate downstream of the annular combustor. Past studies have focused mainly on probe measurements inside the combustor, and thus, little information is known about the nature of the products exiting the RDC. In particular, it is unknown if chemical reactions persist outside the RDC annulus, especially if methane is used as the fuel. In this study, we apply two time-resolved optical techniques to simultaneously image the RDC products at framing rate of 30 kHz: (1) direct visual imaging to identify the overall size and extent of the plume, and (2) OH* chemiluminescence imaging to detect the reaction zones if any. Results show dynamic features of the combustion products that are consistent with the probe measurements inside the RDE. Moreover, presence of OH* in the products suggests that the oblique shock wave and reactions persist downstream of the detonation zone in the RDC.

Carbon and Hydrocarbon Particle Seeding in Air-breathing Rotating Detonation Engine

2021 ◽  
Author(s):  
Robert Burke ◽  
Taha Rezzag ◽  
Kareem Ahmed
Keyword(s):  
Solid Particle ◽  
Gas Turbines ◽  
Carbon Particle ◽  
Department Of Energy ◽  
Peanut Flour ◽  
Noticeable Effect ◽  
Local Flow ◽  
Rotating Detonation Engine ◽  
Detonation Engine ◽  
Rotating Detonation

Abstract Within the power generation community, the rotating detonation engine (RDE) is only growing in popularity with its increased performance, simple mechanism, and operation. Although significant testing is underway to characterize the RDE for integration with conventional gas turbines, this entire system is still at a relatively low technology readiness level. In the midst of RDE research, there is an initiative to understand solid particle seeding effects in the detonation performance. Under investigation at the University of Central Florida is a Department of Energy (DOE) 6 inch RDE, with a solid particle seeder in parallel with its H2 and air flow lines. Previous work on this system involved carbon particle detonation; however, the tested particles were taken one step further to include more sustainable, greener hydrocarbon particles. Testing of powdered sugar, peanut flour, and cornstarch, along with previous carbon black tests have shown not only successful detonability, but a noticeable effect on the detonation wave dynamics. Side by side with a particle burning model being developed, an operational map can be determined for the hydrocarbon particles particularly, which can be tuned with the local flow conditions to achieve peak operability while replacing fuels with sustainable alternatives that could even be grown.

Carbon and Hydrocarbon Particle Seeding in Air-Breathing Rotating Detonation Engine

2021 ◽  
Author(s):  
Robert Burke ◽  
Taha Rezzag ◽  
Kareem A. Ahmed
Keyword(s):  
Solid Particle ◽  
Gas Turbines ◽  
Carbon Particle ◽  
Department Of Energy ◽  
Peanut Flour ◽  
Noticeable Effect ◽  
Local Flow ◽  
Rotating Detonation Engine ◽  
Detonation Engine ◽  
Rotating Detonation

Abstract Within the power generation community, the rotating detonation engine (RDE) is only growing in popularity with its increased performance, simple mechanism, and operation. Although significant testing is underway to characterize the RDE for integration with conventional gas turbines, this entire system is still at a relatively low technology readiness level. In the midst of RDE research, there is an initiative to understand solid particle seeding effects in the detonation performance. Under investigation at the University of Central Florida is a Department of Energy (DOE) 6-inch RDE, with a solid particle seeder in parallel with its H2 and air flow lines. Previous work on this system involved carbon particle detonation; however, the tested particles were taken one step further to include more sustainable, greener hydrocarbon particles. Testing of powdered sugar, peanut flour, and cornstarch, along with previous carbon black tests have shown not only successful detonability, but a noticeable effect on the detonation wave dynamics. Side-by-side with a particle burning model being developed, an operational map can be determined for the hydrocarbon particles particularly, which can be tuned with the local flow conditions to achieve peak operability while replacing fuels with sustainable alternatives that could even be grown.

scholarly journals Numerical Analysis of Detonability Assessment in a Natural Gas-Air Fueled Rotating Detonation Engine

2019 ◽  
Author(s):  
Pankaj Saha ◽  
Peter Strakey ◽  
Donald Ferguson ◽  
Arnab Roy
Keyword(s):  
Natural Gas ◽  
Detonation Wave ◽  
Hydrogen Fuel ◽  
Air Breathing ◽  
Wave Characteristics ◽  
Fuel Blends ◽  
Rotating Detonation Engine ◽  
Continuous Detonation ◽  
Detonation Engine ◽  
Rotating Detonation

Abstract Rotating Detonation Engines (RDE) offer an alternative combustion strategy to replace conventional constant pressure combustion with a process that could produce a pressure gain without the use of a mechanical compressor. Recent numerical and experimental publications that consider air as the oxidizer have primarily focused on the ability of these annular combustors to sustain a stable continuous detonation wave when fueled by hydrogen. However, for this to be a viable consideration for the land-based power generation it is necessary to explore the ability to detonate natural gas and air within the confines of the annular geometry of an RDE. Previous studies on confined detonations have expressed the importance of permitting detonation cells to fully form within the combustor in order to achieve stability. This poses a challenge for natural gas–air fueled processes as their detonation cell size can be quite large even at moderate pressures. Despite the practical importance, only a few studies are available on natural gas detonations for air-breathing RDE applications. Moreover, the extreme thermodynamic condition (high temperature inside the combustor) allows limited accessibility inside the combustor for detailed experimental instrumentations, providing mostly single-point data. Recent experimental studies at the National Energy Technology Laboratory (NETL) have reported detonation failure at higher methane concentration in an air-breathing RDE fueled by natural gas-hydrogen fuel blends. This encourages to perform a detailed numerical investigation on the wave characteristics of detonation in a natural gas-air fueled RDE to understand the various aspects of instability associated with the natural gas-air detonation. This study is a numerical consideration of a methane-air fueled RDE with varying operating conditions to ascertain the ability to achieve a stable, continuous detonation wave. The simulations have been performed in a 2D unwrapped RDE geometry using the open-source CFD library “OpenFOAM” employing an unsteady pressure-based compressible reactive flow solver with a k–ε turbulence model in a structured rectangular grid system. Both reduced and detailed chemical kinetic models have been used to assess the effect of the chemistry on the detonation wave characteristics and the underlying flow features. A systematic grid sensitivity study has been conducted with various grid sizes to quantify the weakly stable overdriven detonation on a coarse mesh and oscillating features at fine mesh resolutions. The main focus of the current study is to investigate the effects of operating injection pressure on detonation wave characteristics of an air-breathing Rotating Detonation Engine (RDE) fueled with natural gas-hydrogen fuel blends. Wave speeds, peak pressures and temperatures, and dominant frequencies have been computed from the time histories. The flow structures were then visualized using 2D contours of temperature and species concentration.

scholarly journals RDE research and development in Poland

Shock Waves ◽  
2021 ◽  
Author(s):  
P. Wolański
Keyword(s):  
International Cooperation ◽  
Rocket Engine ◽  
Combustion Regime ◽  
Combined Cycle ◽  
Liquid Fuels ◽  
Rotating Detonation Engine ◽  
Pressure Gain Combustion ◽  
Detonation Engine ◽  
Basic And Applied Research ◽  
Rotating Detonation

AbstractA very short survey of research conducted in Poland on the development of the rotating detonation engine (RDE) is presented. Initial studies conducted in cooperation with Japanese partners lead to development of a joint patent on RDE. Then, an intensive basic and applied research was started at the Institute of Heat Engineering of the Warsaw University of Technology. One of the first achievements was the demonstration of performance of the rocket engine with an aerospike nozzle utilizing continuously rotating detonation (CRD), and research was directed into development of a small turbofan engine utilizing such a combustion regime. These activities promoted international cooperation and stimulated RDE development not only in Poland but also in other countries. A research directed to measure and calculate flow parameters as well as to analyze the use of liquid fuels was conducted. In the Institute of Aviation in Warsaw, research on the application of the CRD to turbine engines as well as rocket, ramjet, and combined cycle engines was carried out. In the paper, a special emphasis is given to international cooperation in this area with partners from many countries engaged in the development of the pressure gain combustion to propulsion systems.

ON THE MECHANISM FOR MAINTAINING AN OVERDRIVEN DETONATION IN A ROTATING DETONATION ENGINE

2020 ◽  
Author(s):  
P. V. Bulat ◽  
◽  
N. B. Fedosenko ◽  
V. V. Upyrev ◽  
◽  
...  
Keyword(s):  
Thermodynamic Cycle ◽  
Fuel Mixture ◽  
Combustion Products ◽  
Jet Engines ◽  
Entire Volume ◽  
Annular Gap ◽  
Rotating Detonation Engine ◽  
Detonation Engine ◽  
Overdriven Detonation ◽  
Rotating Detonation

At present, virtually all jet engines are based on the Brighton thermodynamic cycle (combustion at constant pressure). The improvement of such engines has already reached its technological limit. A significant increase in the efficiency of jet engines (by 20%-25%) can be provided by a transition to the Fickett-Jacobs[4] thermodynamic cycle which uses detonation combustion. One possible realization is a rotating detonation engine (RDE) in which the combustion chamber is the space between two coaxial cylinders. In an ideal scheme, a fuel mixture is supplied from one end which is ignited by a shock wave rotating in the annular gap with the Chapman-Jouguet velocity, i.e., with a speed equal to the speed of sound relative to the combustion products. It is known that in reality, a much more complex system of gas dynamic discontinuities is formed, consisting of triple configurations of shock waves. Detonation occurs only on the so-called Mach stems and not throughout the entire volume. In this paper, the possibility of creating a traveling overdriven wave by moving an obstacle behind the detonation area is investigated. Particular attention is paid to the initial stage - detonation initiation. A numerical method of the second order of accuracy with a finite rate of chemical reactions is used.

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