CFD Analysis of Hypersonic Combustion of H2-Fueled Scramjet Combustor with Cavity Based Fuel Injector at Flight Mach 6

2014 ◽  
Vol 656 ◽  
pp. 53-63 ◽  
Author(s):  
Krishna Murari Pandey ◽  
Sukanta Roga
Keyword(s):  
Flow Structure ◽  
Combustion Process ◽  
Wave Pattern ◽  
Combustion Efficiency ◽  
Fuel Injector ◽  
Recirculation Flow ◽  
Scramjet Combustor ◽  
Supersonic Mixing ◽  
Stable Flame ◽  
Scramjet Engine

This paper presents a numerical analysis of the inlet-combustor interaction and flow structure through a scramjet engine at a flight Mach 6 with cavity based injection. Fuel is injected at supersonic speed of Mach 2 through a cavity based injector. These numerical simulations are aimed to study the flow structure, supersonic mixing and combustion for cavity based injection. For the reacting cases, the shock wave pattern is modified which is due to the strong heat release during combustion process. The shock structure and combustion phenomenon are not only affected by the geometry but also by the flight Mach number and the trajectory. The inlet-combustor interaction is studied with a fix location of cavity based injection. Cavity is of interest because recirculation flow in cavity would provide a stable flame holding while enhancing the rate of mixing or combustion. The cavity effect is discussed from a view point of mixing and combustion efficiency.

Computational Analysis of Non-Premixed Combustion in a Scramjet Combustor With a Wedge Shaped Strut Injector

2021 ◽  
Author(s):  
Sajal Katare ◽  
Nagendra P. Yadav
Keyword(s):  
Computational Analysis ◽  
Static Pressure ◽  
Computational Study ◽  
Combustion Process ◽  
Combustion Efficiency ◽  
Reaction Model ◽  
Premixed Combustion ◽  
Cold Flow ◽  
Flame Holder ◽  
Scramjet Combustor

Abstract This paper focuses the computational study of non-premixed combustion in a scramjet combustor. The wedge shaped strut injector was used in the combustion process. In order to investigate the flame holding mechanism of the wedge shaped strut in supersonic flow, the two-dimensional coupled implicit RANS equations, the standard k-ε turbulence model and the finite-rate/eddy-dissipation reaction model are introduced to simulate the flow field of the hydrogen fueled scramjet combustor with a strut flame holder under different conditions. The static pressure of the case under the engine ignition condition is much higher than that of the case under the cold flow condition. The reflection of shock waves improves the mixing of hydrogen with the stream of inlet air and thus increases combustion efficiency. The mass flow rate of air is optimized for the best performance of engine.

Investigation of ammonia and hydrogen as CO2-free fuels for heavy duty engines using a high pressure dual fuel combustion process

2020 ◽  
pp. 146808742096787
Author(s):  
Stephanie Frankl ◽  
Stephan Gleis ◽  
Stephan Karmann ◽  
Maximilian Prager ◽  
Georg Wachtmeister
Keyword(s):  
High Pressure ◽  
High Pressures ◽  
Numerical Study ◽  
Combustion Process ◽  
Combustion Efficiency ◽  
Dual Fuel ◽  
Parameter Study ◽  
Fuel Injector ◽  
Cfd Model ◽  
Pilot Fuel

This work is a numerical study of the use of ammonia and hydrogen in a high-pressure-dual-fuel (HPDF) combustion. The main fuels (hydrogen and ammonia) are direct injected and ignited by a small amount of direct injected pilot fuel. The fuels are injected using a dual fuel injector from Woodward L’Orange, which can induce two fuels independently at high pressures up to 1800 bar for the pilot fuel and maximum 500 bar for the main. The numerical CFD-model gets validated for of hydrogen-HPDF with experimental data. Due to safety issues at the test rig it was not possible to use ammonia in the experiments, so it is modelled using the numerical model. It is assumed that the CFD-model also gives qualitative correct results for the use of ammonia as main fuel, so a parameter study of ammonia-HPDF is made. The results for the hydrogen-HPDF show, that hydrogen can be used in the engine without any further modifications. The combustion is very stable, and the hydrogen ignites almost immediately when it enters the combustion chamber. The results of the ammonia combustion indicate, that the HPDF combustion mode can handle ammonia effectively. It seems beneficial to inject the ammonia at higher pressures than hydrogen. Also pre-heating the ammonia can increase the combustion efficiency.

Numerical Study of Scramjet Combustor with Tandem Dual Cavity for Nonreactive Jets

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Ajin Branesh ◽  
Jeevanjot Kaur ◽  
Akashdeep Singh
Keyword(s):  
Numerical Study ◽  
Combustion Efficiency ◽  
Reacting Flows ◽  
Scramjet Combustor ◽  
Different Types ◽  
Mixing Rates ◽  
Varying Length ◽  
Scramjet Engine ◽  
Compressibility Effects ◽  
Convective Mach Number

In the past decades flame out is a major phenomenon that paves way for high fuel consumption in scramjet combustion. For enhancing mixing and flame holding characteristics, different types of cavities are introduced in a scramjet combustion chamber which can hold air for a bit and acts like an atomizer. For increasing combustion efficiency and burnout ratios recirculation is maintained by using cavity and ramp angle techniques. In this paper numerical analysis has been carried out for two dimensional non-reacting flows in the combustor of scramjet engine with tandem dual cavity that creates high turbulent kinetic energy for ensuring combustion instability. This work is an enlightened approach for predicting the flow phenomenon that induces re-circulations after implementing various tandem dual cavities with varying length to diameter ratio and ramp angle. These in turn overcome low mixing rates due to compressibility effects at high convective Mach number.

Numerical Studies on the Performance of Scramjet Combustor with Alternating Wedge-Shaped Strut Injector

2017 ◽  
Vol 34 (1) ◽  
Author(s):  
Gautam Choubey ◽  
K. M. Pandey
Keyword(s):  
Numerical Analysis ◽  
Flow Structure ◽  
Fuel Injection ◽  
Angle Of Attack ◽  
Supersonic Combustion ◽  
Scramjet Combustor ◽  
Numerical Studies ◽  
Scramjet Engine

AbstractNumerical analysis of the supersonic combustion and flow structure through a scramjet engine at Mach 7 with alternating wedge fuel injection and with three angle of attack (

scholarly journals Combustion Optimization for Coal Fired Power Plant Boilers Based on Improved Distributed ELM and Distributed PSO

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1036 ◽  
Author(s):  
Xinying Xu ◽  
Qi Chen ◽  
Mifeng Ren ◽  
Lan Cheng ◽  
Jun Xie
Keyword(s):  
Power Plant ◽  
Combustion Process ◽  
Optimization Method ◽  
Combustion Efficiency ◽  
Pollutant Emissions ◽  
Combustion Model ◽  
Nox Emissions ◽  
Coupling Characteristics ◽  
Learning Machine ◽  
Combustion Optimization

Increasing the combustion efficiency of power plant boilers and reducing pollutant emissions are important for energy conservation and environmental protection. The power plant boiler combustion process is a complex multi-input/multi-output system, with a high degree of nonlinearity and strong coupling characteristics. It is necessary to optimize the boiler combustion model by means of artificial intelligence methods. However, the traditional intelligent algorithms cannot deal effectively with the massive and high dimensional power station data. In this paper, a distributed combustion optimization method for boilers is proposed. The MapReduce programming framework is used to parallelize the proposed algorithm model and improve its ability to deal with big data. An improved distributed extreme learning machine is used to establish the combustion system model aiming at boiler combustion efficiency and NOx emission. The distributed particle swarm optimization algorithm based on MapReduce is used to optimize the input parameters of boiler combustion model, and weighted coefficient method is used to solve the multi-objective optimization problem (boiler combustion efficiency and NOx emissions). According to the experimental analysis, the results show that the method can optimize the boiler combustion efficiency and NOx emissions by combining different weight coefficients as needed.

scholarly journals Combustion Thermodynamics of Ethanol, n-Heptane, and n-Butanol in a Rapid Compression Machine with a Dual Direct Injection (DDI) Supply System

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2729
Author(s):  
Ireneusz Pielecha ◽  
Sławomir Wierzbicki ◽  
Maciej Sidorowicz ◽  
Dariusz Pietras
Keyword(s):  
Heat Release ◽  
Combustion Chamber ◽  
Internal Combustion Engines ◽  
Direct Injection ◽  
Combustion Process ◽  
Combustion Efficiency ◽  
Injection System ◽  
Rapid Compression Machine ◽  
Process Indicators ◽  
Rapid Compression

The development of internal combustion engines involves various new solutions, one of which is the use of dual-fuel systems. The diversity of technological solutions being developed determines the efficiency of such systems, as well as the possibility of reducing the emission of carbon dioxide and exhaust components into the atmosphere. An innovative double direct injection system was used as a method for forming a mixture in the combustion chamber. The tests were carried out with the use of gasoline, ethanol, n-heptane, and n-butanol during combustion in a model test engine—the rapid compression machine (RCM). The analyzed combustion process indicators included the cylinder pressure, pressure increase rate, heat release rate, and heat release value. Optical tests of the combustion process made it possible to analyze the flame development in the observed area of the combustion chamber. The conducted research and analyses resulted in the observation that it is possible to control the excess air ratio in the direct vicinity of the spark plug just before ignition. Such possibilities occur as a result of the properties of the injected fuels, which include different amounts of air required for their stoichiometric combustion. The studies of the combustion process have shown that the combustible mixtures consisting of gasoline with another fuel are characterized by greater combustion efficiency than the mixtures composed of only a single fuel type, and that the influence of the type of fuel used is significant for the combustion process and its indicator values.

Hydrogen fueled scramjet combustor with a wavy-wall double strut fuel injector

Fuel ◽  
2021 ◽  
Vol 304 ◽  
pp. 121425
Author(s):  
Obula Reddy Kummitha ◽  
K.M. Pandey
Keyword(s):  
Wavy Wall ◽  
Fuel Injector ◽  
Scramjet Combustor

Combustion of Coal/Water Mixtures With Thermal Preconditioning

1987 ◽  
Vol 109 (3) ◽  
pp. 313-318 ◽  
Author(s):  
M. Novack ◽  
G. Roffe ◽  
G. Miller
Keyword(s):  
Gas Turbine ◽  
Combustion Efficiency ◽  
Experimental Program ◽  
Water Mixture ◽  
Gas Turbine Combustor ◽  
Hydrocarbon Gases ◽  
Sampling Probe ◽  
Stable Flame ◽  
Thermal Preconditioning ◽  
Gaseous Form

Thermal preconditioning is a process in which coal/water mixtures are vaporized to produce coal/steam suspensions, and then superheated to allow the coal to devolatilize producing suspensions of char particles in hydrocarbon gases and steam. This final product of the process can be injected without atomization, and burned directly in a gas turbine combustor. This paper reports on the results of an experimental program in which thermally preconditioned coal/water mixture was successfully burned with a stable flame in a gas turbine combustor test rig. Tests were performed at a mixture flowrate of 300 lb/hr and combustor pressure of 8 atm. The coal/water mixture was thermally preconditioned and injected into the combustor over a temperature range from 350°F to 600°F, and combustion air was supplied at between 600°F to 725°F. Test durations varied between 10 and 20 min. Major results of the combustion testing were that: A stable flame was maintained over a wide equivalence ratio range, between φ = 2.2 (rich) and 0.2 (lean); and combustion efficiency of over 99 percent was achieved when the mixture was preconditioned to 600°F and the combustion air preheated to 725°F. Measurements of ash particulates, captured in the exhaust sampling probe located 20 in. from the injector face, show typical sizes collected to be about 1 μm, with agglomerates of these particulates to be not more than 8 μm. The original mean coal particle size for these tests, prior to preconditioning, was 25 μm. Results of additional tests showed that one third of the sulfur contained in the solids of a coal/water mixture with 3 percent sulfur was evolved in gaseous form (under mild thermolized conditions) mainly as H2S with the remainder as light mercaptans.

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