Continuous Detonation Engine Researches at Peking University

2017 ◽  
pp. 161-182
Author(s):  
Jian-Ping Wang ◽  
Song-Bai Yao ◽  
Xu-Dong Han
Keyword(s):  
Continuous Detonation ◽  
Peking University ◽  
Detonation Engine

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.

Tip to End Analysis of Air Breathing Rotating Detonation Engine System

2019 ◽  
Vol 11 (5) ◽  
Author(s):  
P. Amrutha Preethi ◽  
V. Ramanujachari
Keyword(s):  
Detonation Wave ◽  
Air Breathing ◽  
System A ◽  
Rotating Detonation Engine ◽  
Continuous Detonation ◽  
Simulation Based ◽  
Detonation Engine ◽  
Air Intake ◽  
Expansion System ◽  
Rotating Detonation

A discovery was made recently that the heat release would be very efficient if it is associated with detonation phenomenon. A detonation wave imparts high pressure to the products of combustion which in turn produces large propulsive power as a result of expansion through the propulsive element. This kind of pressure gain combustor is a new idea which is going to be incorporated in the futuristic propulsive devices. A representative air breathing propulsive system configuration powered by the continuous detonation wave engine is chosen for the present investigation. This includes understanding of various processes occurring in the air intake, isolator, rotating detonation wave engine and flow expansion system. A detailed numerical modelling and simulation based on steady 1-D flow have been carried out. This analysis gave insight into the overall propulsion system performance taking into consideration of the interaction between various sub systems.

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.

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