Journal articles: 'Ramjet engines'

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Liu, K., and T. Cui. "Combustor-inlet interactions in a low-order dynamic model of ramjet engines." Aeronautical Journal 124, no. 1282 (July 29, 2020): 2001–18. http://dx.doi.org/10.1017/aer.2020.64.

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ABSTRACTThe coexistence of multiple stable states is indicative of self-organising processes occurring in the course of the combustor-inlet interactions in a ramjet engine and give rise to the appearance of various nonlinear phenomena. This paper provides a dynamic model that can describe the multiple stable states and the corresponding nonlinear effects to further investigate the dynamic interactions between combustor and inlet in a ramjet engine. Our study shows the whole engine can display distinct dynamic behaviours ranging from irreversibility to hysteresis and to various mode transitions, depending on different physical parameters. With the model, we also illustrate the role of the instability of the normal shock wave in impacting the whole engine’s nonlinear dynamics. Additionally, we extend the previous studies of the classification of combustor-inlet interactions from a static framework to a dynamic framework, which helps to clarify the transient processes of the nonlinear interactions. This work offers a quantitative illustration of the combustor-inlet interactions in a ramjet engine by revealing its nonlinear dynamics and associated characteristics, therefore advancing our understanding of the nonlinear phenomena that exhibit in ramjet engines.

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FUNAKI, Katsumi. "Characteristics of ramjet engines." Journal of the Japan Society for Aeronautical and Space Sciences 35, no. 402 (1987): 329–38. http://dx.doi.org/10.2322/jjsass1969.35.329.

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Zhao, Dongsheng, Zhijun Wei, Duanyang He, Li Dalin, and Huang Chujiu. "Effect of different particle sizes on combustion characteristics of DCR engines." Journal of Physics: Conference Series 2746, no. 1 (May 1, 2024): 012012. http://dx.doi.org/10.1088/1742-6596/2746/1/012012.

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Abstract The ramjet engine has undergone rapid development in recent decades, and the dual combustion chamber ramjet (DCR) engine was proposed in the last century. Boron, with its high volumetric and gravimetric heating values, is one of the most attractive fuel additives for ramjet engines. However, due to the problem of low combustion efficiency, boron is difficult to achieve high efficiency combustion in practical applications. In order to investigate the combustion characteristics of boron-containing gas solid phase components in DCR engines, the Realizable k-ε model, finite rate/vortex dissipation model and boron particle King model ignition combustion calculation program were written. A three-dimensional full-scale two-phase flow numerical simulation was carried out in the combustion chamber of the DCR engine to calculate the effects of different particle sizes on the combustion characteristics. Through the analysis of the simulation results, the particle size affects the ignition time of boron particles and is positively correlated with the combustion efficiency, but with a non-linear growth. A smaller particle size can promote the ignition of boron particles, improve the solid phase combustion efficiency and achieve efficient combustion.

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Кислов, Олег Владимирович, and Михаил Анатольевич Шевченко. "ОСОБЕННОСТИ РАСЧЕТА И РЕГУЛИРОВАНИЯ ДВУХКОНТУРНОГО ТУРБОРЕАКТИВНОГО ДВИГАТЕЛЯ С ФОРСАЖНОЙ КАМЕРОЙ СГОРАНИЯ В НАРУЖНОМ КОНТУРЕ НА ПРЯМОТОЧНЫХ РЕЖИМАХ РАБОТЫ." Aerospace technic and technology, no. 6 (November 27, 2020): 15–23. http://dx.doi.org/10.32620/aktt.2020.6.02.

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A promising direction in aviation is the creation of anaircraft for supersonic cruise speeds (Mach 3...4). It is known that ramjet engines are more preferable for Mach numbers larger 3. However, they do not have starting thrust and uneconomical at subsonic flight speeds. At the same time, at subsonic flight speeds, turbofan engines are the most expedient. The combination of the positive properties of turbofan engines at subsonic speeds and a ramjet engines at supersonic speeds is possible by using duct-burning turbofan engine, which can operate at the ramjet mode with the blocked gas turbine duct at supersonic flight conditions. At this mode, duct-burning turbofan engine turns into ramjet engine, which, however, has special features due to the presence of fan in front of the combustion chamber, which operates in turbine mode or in zero power mode and also because of the outlet jet, which has annular shape, flows out from the duct causes the appearance of bottom drag. The presence of bottom drag requires both the development of a mathematical model for its calculation and taking into account its influence on the choice of the control law for the nozzle outlet area. The article presents a mathematical model of the working process of duct-burning turbofan engine at ramjet mode, taking into account the presence of fan in the flow path and bottom drug. Using the developed mathematical model, the regularities of changes in the internal and effective thrust, as well as the specific fuel consumption, depending on the relative fuel consumption and the critical section of the nozzle at a given altitude and flight speed are established. The critical section of the nozzle is the main regulating factor, and the relative fuel consumption is related to the main regulating factor - the fuel consumption. These patterns are useful for choosing a control program.There is such a combination of regulating factors whichprovides two extremes in the regularities of trust and specific fuel consumption changes: the mode of minimum specific fuel consumption and the mode of maximum thrust. In addition, the influence of gas underexpansion in the nozzle on the thrust-economic parameters of the engine and the required area of the nozzle outlet section were estimated. The obtained regularities are advisable to use when engine control program is chosen.

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Hu, Lichen, Feiyu Long, Borui Xie, and Xuanzhou Zhuang. "Four variants of turbofan, turbojet, turboprop and ramjet engines and their future prospects." Applied and Computational Engineering 11, no. 1 (September 25, 2023): 137–42. http://dx.doi.org/10.54254/2755-2721/11/20230222.

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A jet engine is a sophisticated machine that has revolutionized the aviation industry. It is a type of internal combustion engine that uses air as its oxidizer and fuel to produce thrust. The third law of motion, which states that there is an equivalent and opposite response to every action, governs how the engine functions. Compressed air is combined with fuel, ignited in the combustion chamber, and then expelled out of the jet engine at a high rate of speed to create propulsion. The development of jet engines has been a long and arduous process, with many different designs and configurations over the years. Early jet engines were inefficient, noisy, and prone to failure. However, technological advances have created more efficient and reliable engines in various applications, from commercial aviation to military aircraft and even spacecraft. The efficiency and reliability of jet engines have transformed air travel, enabling faster and more efficient travel over long distances. This has increased global connectivity, economic growth, and cultural exchange. However, jet engines also have environmental impacts, such as noise pollution and greenhouse gas emissions, which have led to the development of more environmentally friendly engines.

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Fureby, Christer, Guillaume Sahut, Alessandro Ercole, and Thommie Nilsson. "Large Eddy Simulation of Combustion for High-Speed Airbreathing Engines." Aerospace 9, no. 12 (December 1, 2022): 785. http://dx.doi.org/10.3390/aerospace9120785.

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Large Eddy Simulation (LES) has rapidly developed into a powerful computational methodology for fluid dynamic studies, between Reynolds-Averaged Navier–Stokes (RANS) and Direct Numerical Simulation (DNS) in both accuracy and cost. High-speed combustion applications, such as ramjets, scramjets, dual-mode ramjets, and rotating detonation engines, are promising propulsion systems, but also challenging to analyze and develop. In this paper, the building blocks needed to perform LES of high-speed combustion are reviewed. Modelling of the unresolved, subgrid terms in the filtered LES equations is highlighted. The main families of combustion models are presented, focusing on finite-rate chemistry models. The density-based finite volume method and the reaction mechanisms commonly employed in LES of high-speed H2-air combustion are briefly reviewed. Three high-speed combustor applications are presented: an experiment of supersonic flame stabilization behind a bluff body, a direct connect facility experiment as a transition case from ramjet to scramjet operation mode, and the STRATOFLY MR3 Small-Scale Flight Experiment. Several combinations of turbulence and combustion models are compared. Comparisons with experiments are also provided when available. Overall, the results show good agreement with experimental data (e.g., shock train, mixing, wall heat flux, transition from ramjet to scramjet operation mode).

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Avrashkov, V. N., E. S. Metelkina, and D. V. Meshcheryakov. "Investigation of High-Speed Ramjet Engines." Combustion, Explosion, and Shock Waves 46, no. 4 (July 2010): 400–407. http://dx.doi.org/10.1007/s10573-010-0054-0.

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Buchanan, C. R., A. J. T. Gemmill, and P. G. Martin. "Interaction of missile propulsion and aerodynamics." Aeronautical Journal 104, no. 1036 (June 2000): 271–77. http://dx.doi.org/10.1017/s0001924000091594.

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Abstract Some aspects of propulsion integration issues for ramjet powered missiles are outlined in this paper. The benefits of ramjet propulsion in the Mach 2-4 range over other types of airbreathing propulsion and rocket propulsion are well known. Compared with solid rocket motors, ramjet engines offer a much higher specific impulse and the capability of thrust management, enabling longer stand-off ranges and more flexible operation. An overview of the ramjet engine cycle is given, highlighting engine/intake matching issues. This is followed by a performance comparison between a generic ramjet and a solid rocket powered missile (the air-to-air configuration is examined by way of example in this paper). As well as overall performance, intake integration and missile steering issues are considered. A description of a wind tunnel test model, intake design and tunnel testing is given. The effects of design Mach number and side-wall removal have been investigated for twin ventral rectangular intake configurations. These tests were aimed at optimising performance at different flight conditions and improving tolerance to yawed flight. The impact of the alternative intake designs on missile performance is discussed.

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Timoshenko, V. I., V. P. Halynskyi, and Yu V. Knyshenko. "Theoretical studies on rocket/space hardware aerogas dynamics." Technical mechanics 2021, no. 2 (June 29, 2021): 46–59. http://dx.doi.org/10.15407/itm2021.02.046.

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This paper presents the results of theoretical studies on rocket/space hardware aerogas dynamics obtained from 2016 to 2020 at the Department of Aerogas Dynamics and Technical Systems Dynamics of the Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine along the following lines: rocket aerodynamics, mathematical simulation of the aerogas thermodynamics of a supersonic ramjet vehicle, jet flows, and the hydraulic gas dynamics of low-thrust control jet engines. As to rocket aerodynamics, computational methods and programs (CMPs) were developed to calculate supersonic flow past finned rockets. The chief advantage of the CMPs developed is computational promptness and ease of adding wings and control and stabilization elements to rocket configurations. A mathematical simulation of the aerogas thermodynamics of a supersonic ramjet vehicle yielded new results, which made it possible to develop a prompt technique for a comprehensive calculation of ramjet duct flows and generalize it to 3D flow past a ramjet vehicle. Based on marching methods, CMPs were developed to simulate ramjet duct flows with account for flow past the airframe upstream of the air inlet, the effect of the combustion product jet on the airframe tail part, and its interaction with a disturbed incident flow. The CMPs developed were recommended for use at the preliminary stage of ramjet component shape selection. For jet flows, CMPs were developed for the marching calculation of turbulent jets of rocket engine combustion products with water injection into the jet body. This made it possible to elucidate the basic mechanisms of the effect of water injection, jet–air mixing, and high-temperature rocket engine jet afterburning in atmospheric oxygen on the flow pattern and the thermogas dynamic and thermalphysic jet parameters. CMPs were developed to simulate the operation of liquid-propellant low-thrust engine systems. They were used in supporting the development and ground firing tryout of Yuzhnoye State Design Office’s radically new system of control jet engines fed from the sustainer engine pipelines of the Cyclone-4M launch vehicle upper stage. The computed results made it possible to increase the informativity of firing test data in flight simulation. The CMPs developed were transferred to Yuzhnoye State Design Office for use in design calculations.

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Bogomolov, Iaroslav, and Vladimir Malinin. "DETERMINATION OF BREAKING CHARACTERISTICS IN THE PRE-COMBUSTION CHAMBER OF A COMBINED RAMJET ENGINE ON A POWDERED ALUMINUM FUEL TAKING INTO ACCOUNT AIR BRAKING IN AIR INTAKE DEVICE." Perm National Research Polytechnic University Aerospace Engineering Bulletin, no. 65 (2021): 105–11. http://dx.doi.org/10.15593/2224-9982/2021.65.11.

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The paper considers a combined ramjet engine powered by powdered aluminum fuel . The prototype was a combined solid-fuel ramjet engine. The advantages of the engine under consideration are given. An example of the combustion of finely dispersed aluminum powder is considered, from which it follows that the initial temperature of the aluminum powder will affect the stall characteristics in the pre-chamber. The following characteristics of the PAF ramjet were determined: the temperature of air stagnation in the air intake device, the temperature of the mixture of aluminum powder and the stalled air flow, the excess air ratio, and the stall characteristics in the pre-chamber taking into account the air stagnation temperatures. All parameters are de-termined for engine operating altitudes equal to 0.5, 10 and 18 km. A comparison is made of the limiting flame propagation ve-locities under standard conditions and with an incident air flow. Based on the obtained values of the characteristics, the interval of values of the coefficient of air sampling from the inlet to the pre-chamber of the ramjet engine on the PAF was determined, corresponding to the maximum possible areas of the engine operating parameters. Using the obtained values of characteristics, the combustion process of powdered aluminum in the pre-chamber of a ramjet engine takes place without flame blowout, which excludes unstable operation of the propulsion system as a whole. The use of powdered aluminum makes it possible to regulate the thrust in a wide range of values, and a high initial temperature of the air entering the pre-chamber for repeated switching on and off of the engine. Based on the available data, the type of engines under consideration is suitable for combat missiles of various classes, but the most suitable for aircraft-based missiles.

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Senkevich, Alexander P. "A Ramjet Relativistic Engine - a Hypothesis for Discussion." AEROSPACE SPHERE JOURNAL, no. 4 (December 15, 2020): 80–87. http://dx.doi.org/10.30981/2587-7992-2020-105-4-80-87.

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In this paper, the engineering and scientific community is invited to consider and discuss the possibility of developing and constructing a ramjet engine for movement in the interstellar medium when the speeds of an aircraft are close to the speed of light. The idea is based on existing developments in high energy physics and accelerator technology. For interstellar flight, a motion scheme is proposed using accelerated relativistic high-energy protons to create efficient jet engines based on accelerating superconducting structures. The proposed scheme is based on the existing developments in the field of accelerator technology, using superconducting resonator systems, klystrons and high-frequency generators. The use of the impulse of the relativistic motion of charged particles is proposed as a hypothesis for discussing the design of a direct-flow engine for motion in the interstellar medium.

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Zellner, B., W. Sterr, and O. Herrmann. "Integration of Turbo-Expander and Turbo-Ramjet Engines in Hypersonic Vehicles." Journal of Engineering for Gas Turbines and Power 116, no. 1 (January 1, 1994): 90–97. http://dx.doi.org/10.1115/1.2906815.

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Turbo-expander-ramjet and turbo-ramjet are two engine concepts considered for hypersonic aircraft designs with a flight regime between Mach 0 and 7. To establish any performance or integration aspects for these two combined-cycle engine types, an extended study of a variety of influence parameters is necessary, because the interaction between aircraft and propulsion system is even stronger than on conventional aircraft. In fact, the propulsion system is very sensitive to intake and nozzle/afterbody design at these high speeds. This paper presents the engine configurations chosen for comparison and describes the computer program used for the propulsion system performance simulation, including all relevant integration aspects. Furthermore, some results of propulsion system performance for a generic hypersonic aircraft and a typical ascent profile will be compared to indicate the special characteristics of the engines. Finally, some thoughts concerning the suitability and relevant technological requirements of the two engine types—seen from an aircraft manufacturer’s view—are included. The paper includes the results of two diploma theses, written by W. Sterr [1] and B. Zellner [2] at the Technical University of Munich, supervised by Prof. H. Rick (LFA) and O. Herrmann (MBB).

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Pismennyi, V. L. "Hyper Afterburner Jet Engines." Proceedings of Higher Educational Institutions. Маchine Building, no. 01 (718) (January 2020): 51–62. http://dx.doi.org/10.18698/0536-1044-2020-1-51-62.

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This paper introduces a thrust augmentation method for super- and hypersonic jet engines by means of applying water at the engine intake. This method expands the use of jet engines with subsonic combustion, allowing velocities up to Mach 8 and altitude up to 45 km. At velocities higher than 3–4 Mach, stagnation temperature of the air is getting higher than the critical temperature of water, which makes the existence of water at the gas turbine engine intake impossible. Water vapour as a working medium of a jet engine creates the so-called inner thermodynamic circle. This phenomenon defines the physics of the thrust augmentation method proposed. The author discusses three variants of hyper afterburner application: hyper afterburner turbojet, hyper afterburner ramjet, and hyper afterburner turbo ejecting engine. The presented basic specifications of the hyper afterburner engines qualitatively differ from those of their prototypes (engines without the hyper afterburner thrust augmentation function). The proposed thrust augmentation method of jet engines is of a special interest for the aerospace field, particularly, for creating air launch systems. It is shown that the application of hyper afterburner in turbo ejecting engines can increase velocity and altitude of the launch aircraft up to Mach 7 and 40 km respectively, thus opening new avenues in space exploration.

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Barta, J., S. Shani, J. Litani, and R. Chaim. "ZrO2Y2O3 ceramic nozzle throats for ramjet engines." Materials Science and Engineering 71 (May 1985): 303. http://dx.doi.org/10.1016/0025-5416(85)90240-x.

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Ma, Kaifu, Zijian Zhang, Yunfeng Liu, and Zonglin Jiang. "Aerodynamic principles of shock-induced combustion ramjet engines." Aerospace Science and Technology 103 (August 2020): 105901. http://dx.doi.org/10.1016/j.ast.2020.105901.

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Cui, Tao, and Shunlin Tang. "Geometry Rule of Combustor–Inlet Interaction in Ramjet Engines." Journal of Propulsion and Power 30, no. 2 (March 2014): 449–60. http://dx.doi.org/10.2514/1.b34892.

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Tunik, Yu V., and V. O. Mayorov. "Energy efficiency of detonation combustion in supersonic ramjet engines." Acta Astronautica 194 (May 2022): 488–95. http://dx.doi.org/10.1016/j.actaastro.2021.09.038.

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Levi, Reuben VR, and Amrutha Rajamani. "Study on Performance of Ramjet Intake by Changing the Cowl Angle." IOP Conference Series: Materials Science and Engineering 1258, no. 1 (October 1, 2022): 012042. http://dx.doi.org/10.1088/1757-899x/1258/1/012042.

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Most gas turbine engines require the Mach range on the engine face to be at a mild subsonic pace (around Mach 04). Therefore, for a supersonic plane with a gas turbine engine, the characteristic of the air inlet is to slow the supersonic unfastened flow to a subsonic pace and offer a matched air mass float charge to the engine. The gas turbine engine calls for the delivery of uniform excessive general stress restoration air for proper overall performance and operation because the quality of the airflow on the engine face substantially influences the overall performance of the engine, in particular, the total stress loss, which influences the engine thrust and therefore the gasoline consumption. A 2-D supersonic intake is designed for Mach No. 2.4 at an altitude of 11,000 m. The design of the mixed compression supersonic intake is done numerically, and the design with the k- turbulent module is done using CFD. Optimization of the intake is done by changing the cowl deflection in order to get maximum total pressure recovery. Results are compared to knowing the optimal design. The main advantage of mixed compression is that it gives the maximum total pressure recovery at any Mach number. The computation is done with the ANSYS software.

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Crump, James E., Klaus C. Schadow, Vigor Yang, and Fred E. C. Culick. "Longitudinal combustion instabilities in ramjet engines Identification of acoustic modes." Journal of Propulsion and Power 2, no. 2 (March 1986): 105–9. http://dx.doi.org/10.2514/3.22852.

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Yang, Yajing, and Maogang He. "Thermodynamic cycle analysis of ramjet engines using magnesium-based fuel." Aerospace Science and Technology 22, no. 1 (October 2012): 75–84. http://dx.doi.org/10.1016/j.ast.2011.06.005.

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Amar, S., and Reddy T. Gowtham Manikanta. "Air Breathing Rocket Engines and Sustainable Launch Systems." Applied Mechanics and Materials 232 (November 2012): 310–15. http://dx.doi.org/10.4028/www.scientific.net/amm.232.310.

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An air-breathing rocket engine inhales oxygen from the air for about half the flight, so it doesn't have to store the gas onboard. So at take-off, an air-breathing rocket weighs much less than a conventional rocket, which carries all of its fuel and oxygen onboard. Air breathing rockets, combine the performance characteristics of both rocket and ramjet engines. An air-breathing engine gets its initial take-off power from specially designed rockets, called air-augmented rockets, that boost performance about 15 percent over conventional rockets. When the vehicle's velocity reaches twice the speed of sound, the rockets are turned off and the engine relies totally on oxygen in the atmosphere to burn the hydrogen fuel. Once the vehicle's speed increases to about 10 times the speed of sound, the engine converts to a conventional rocket-powered system to propel the vehicle into orbit. And therefore reducing a vehicle's weight decreases cost significantly. And since an air breathing engine cannot get required initial take off thrust, various launch types like air augmented rockets, horizontal launch mode courtesy hybrid engine, magnetic levitation launch systems are used for initial thrust requirements ,thus reducing fuel emissions and increases net efficiency of rockets. Hence air breathing engines can be implemented to address energy considerations and reduce costs.

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Shao, Shiyao, Songchen Yue, Hong Qiao, Peijin Liu, and Wen Ao. "Numerical and Experimental Analyses of the Effect of Water Injection on Combustion of Mg-Based Hydroreactive Fuels." Aerospace 11, no. 7 (July 1, 2024): 542. http://dx.doi.org/10.3390/aerospace11070542.

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The energy release process of the Mg-based hydroreactive fuels directly affects the performance of water ramjet engines, and the burning rate is one of the key parameters of the Mg-based hydroreactive fuels. However, there is not enough in-depth understanding of the combustion process of Mg-based hydroreactive fuels within the chamber of water ramjet engines, and there is a lack of effective means of prediction of the burning rate. Therefore, this paper aims to examine the flame structure of Mg-based hydroreactive fuels with a high metal content and analyze the impact of the water injection velocity and droplet diameter on the combustion property. A combustion experiment system was designed to replicate the combustion of Mg-based hydroreactive fuels within water ramjet engines, and the average linear burning rate was calculated through the target line method. On the basis of the experiment, a combustion–flow coupling solution model of Mg-based hydroreactive fuels was formulated, including the reaction mechanism between Mg/H2O and the decomposition products from an oxidizer and binder. The model was validated through experimental results with Mg-based hydroreactive fuels at various pressures and water injection velocities. The mean absolute percentage error (MAPE) in the experimental results was less than 5%, proving the accuracy and validity of the model. The resulting model was employed for simulating the combustion of Mg-based hydroreactive fuels under different water injection parameters. The addition of water injection resulted in the creation of a new high-temperature region, namely the Mg/H2O non-premixed combustion region in addition to improving the radial diffusion of the flame. With the increasing water injection velocity, the characteristic distance of Mg/H2O non-premixed combustion region is decreased, which enhances the heat transfer to burning surface and accelerates the fuel combustion. The impact of droplet parameters was investigated, revealing that larger droplets enhance the penetration of the fuel-rich gas, which is similar to the effect of injection velocity. However, when the droplet size becomes too large, the aqueous droplets do not fully evaporate, resulting in a slight decrease in the burning rate. These findings enhance the understanding of the mechanisms behind the burning rate variation in Mg-based hydroreactive fuels and offer theoretical guidance for the optimal selection of the engine operating parameters.

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Min, Chen, Tang Hailong, and Zhu Zhili. "Goal Programming for Stable Mode Transition in Tandem Turbo-ramjet Engines." Chinese Journal of Aeronautics 22, no. 5 (October 2009): 486–92. http://dx.doi.org/10.1016/s1000-9361(08)60130-2.

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Wolański, P. "RDE research and development in Poland." Shock Waves 31, no. 7 (October 2021): 623–36. http://dx.doi.org/10.1007/s00193-021-01038-2.

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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.

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Åkerblom, Arvid, Martin Passad, Alessandro Ercole, Niklas Zettervall, Elna J. K. Nilsson, and Christer Fureby. "Numerical Modeling of Chemical Kinetics, Spray Dynamics, and Turbulent Combustion towards Sustainable Aviation." Aerospace 11, no. 1 (December 28, 2023): 31. http://dx.doi.org/10.3390/aerospace11010031.

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With growing interest in sustainable civil supersonic and hypersonic aviation, there is a need to model the combustion of alternative, sustainable jet fuels. This work presents numerical simulations of several related phenomena, including laminar flames, ignition, and spray flames. Two conventional jet fuels, Jet A and JP-5, and two alternative jet fuels, C1 and C5, are targeted. The laminar burning velocities of these fuels are predicted using skeletal and detailed reaction mechanisms. The ignition delay times are predicted in the context of dual-mode ramjet engines. Large Eddy Simulations (LES) of spray combustion in an aeroengine are carried out to investigate how the different thermodynamic and chemical properties of alternative fuels lead to different emergent behavior. A novel set of thermodynamic correlations are developed for the spray model. The laminar burning velocity predictions are normalized by heat of combustion to reveal a more distinct fuel trend, with C1 burning slowest and C5 fastest. The ignition results highlight the contributions of the Negative Temperature Coefficient (NTC) effect, equivalence ratio, and hydrogen enrichment in determining ignition time scales in dual-mode ramjet engines. The spray results reveal that the volatile alternative jet fuels have short penetration depths and that the flame of the most chemically divergent fuel (C1) stabilizes relatively close to the spray.

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Cui, Tao, Shunlin Tang, Chao Zhang, and Daren Yu. "Hysteresis Phenomenon of Mode Transition in Ramjet Engines and Its Topological Rules." Journal of Propulsion and Power 28, no. 6 (November 2012): 1277–84. http://dx.doi.org/10.2514/1.b34419.

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Dulepov, N. P., A. I. Lanshin, A. V. Lukovnikov, V. L. Semenov, G. D. Kharchevnikova, D. B. Fokin, and P. S. Suntsov. "Effectiveness of two-mode hypersonic ramjet engines in hybrid aerospace power units." Russian Engineering Research 31, no. 8 (August 2011): 764–70. http://dx.doi.org/10.3103/s1068798x11080090.

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Козел, Дмитрий Викторович. "Выбор геометрических характеристик фронтового устройства и длины камеры сгорания прямоточного типа." Aerospace technic and technology, no. 4sup2 (August 27, 2021): 19–28. http://dx.doi.org/10.32620/aktt.2021.4sup2.03.

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A method has been developed for selecting the geometric characteristics of the front and the length of the direct-flow combustion chamber. Afterburner combustion chambers are of the ramjet type and are used for a short-term increase in the thrust of a gas turbine engine during takeoff, for overcoming the sound barrier by an aircraft and for flying at supersonic speed, and for making maneuvers. As part of ramjet engines, ramjet combustion chambers are used as the main combustion chambers in which the process of fuel combustion and heat supply to the working fluid is ensured. The developed method for selecting the geometric characteristics consists in optimizing the main operating characteristics of the combustion chamber. Mathematical models are proposed for describing the dependence of the total pressure loss, the combustion efficiency and the range of stable operation of the combustion chamber against the parameters of the flow at the inlet to the combustion chamber and the geometric characteristics of the front device and the length of the combustion chamber. The analysis of the dependences of the combustion chamber working characteristics on the geometric characteristics of the front-line device and its length is carried out. As a result of the analysis of mathematical models, a list of the main geometric characteristics of the front device was determined, on which the total pressure loss, the combustion efficiency and the range of stable operation of the combustion chamber depend. Optimization parameters, optimization criterion and limits for solving the optimization problem are determined. As an implementation of the optimization method, it is proposed to use a diagram of the combustion chamber performance in the coordinates of the optimization parameters. The developed method makes it possible to ensure the optimal basic operating characteristics of the combustion chamber - total pressure loss, combustion efficiency and combustion stability limits.

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Guo, Feng, Ming Liu, Guozhong He, Junhui Zhou, Jianfeng Zhu, and Yancheng You. "Analysis and Suppression of Thrust Trap for Turbo-Ramjet Mode Transition with the Integrated Optimal Control Method." Aerospace 10, no. 8 (July 27, 2023): 667. http://dx.doi.org/10.3390/aerospace10080667.

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An aircraft/engine integrated optimal control method is proposed for turbine-based combined cycle (TBCC) engines based on the Gauss pseudospectral method. The optimal flight trajectory and TBCC control law are obtained for a TBCC-powered aircraft, and the “thrust trap” that occurs during turbo-ramjet mode transition is further analyzed and suppressed. Results show that the aircraft goes through the mode transition phase using a “climb-dive” trajectory, which is a strategy of applying gravity-assist and temporarily reducing the drag. Furthermore, the TBCC engine adjusts at the quickest rate to minimize thrust loss. With the coupling of the trajectory and TBCC control law, the minimum thrust during the mode transition is only 23% of the thrust before the mode transition, suggesting the “thrust trap” phenomenon. By decreasing the mode transition time from 60 s to 15 s, the minimum thrust can only increase to 30%, and the “thrust trap” phenomenon cannot be effectively suppressed. When the operating speed range of the turbine engine increases from Ma2.5 to 2.9, the minimum thrust will reach 80%, and the “thrust trap” tends to level off.

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30

Li, Chunlei, Yingkun Li, Weixuan Li, Liang Zhu, Xiong Chen, Shuifeng Yang, and Yan Wu. "Numerical investigation on fluid characteristics of supersonic mixing layers with splitter plate in a confined space." Journal of Physics: Conference Series 2235, no. 1 (May 1, 2022): 012063. http://dx.doi.org/10.1088/1742-6596/2235/1/012063.

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Abstract High-speed airbreathing engines has been going on for more than a century, since French engineer Reina Lauren first developed the concept of the ramjet. Kelvin-Helmholtz (K-H) instability and compressibility effects on the evolution of supersonic mixing layer growing rate have been widely investigated in experimental and computational ways. The present study proposed a quasi-DNS solver which is written in Fortran 90, the mixing process of the supersonic planar mixing layers is analyzed in detail, especially, the process of the vortex rolling up, stretching, pairing and merging are also reported in present study. It is noteworthy that the mechanisms of K-H instability are analysed in detail, and the baroclinic term has a great influence on the growth of the supersonic mixing layer in confined space.

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Yanovskii, L. S., D. B. Lempert, V. V. Raznoschikov, I. S. Averkov, I. N. Zyuzin, A. F. Zholudev, and M. B. Kislov. "Prospects for the use of diethynylbenzene as a fuel dispersant for rocket ramjet engines." Russian Chemical Bulletin 68, no. 10 (October 2019): 1848–55. http://dx.doi.org/10.1007/s11172-019-2634-9.

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32

Du, Zhao-bo, Wei Huang, and Li Yan. "Investigation on gaseous jet in forebody/inlet for shock-induced combustion ramjet (shcramjet) engines." Acta Astronautica 152 (November 2018): 262–74. http://dx.doi.org/10.1016/j.actaastro.2018.08.030.

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Ispir, Ali Can, Pedro Miguel Gonçalves, and Bayindir H. Saracoglu. "Analysis of a combined cycle propulsion system for STRATOFLY hypersonic vehicle over an extended trajectory." MATEC Web of Conferences 304 (2019): 03001. http://dx.doi.org/10.1051/matecconf/201930403001.

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Hypersonic civil aviation is an important enabler for extremely shorter flight durations for long-haul routes and using unexploited flight altitudes. Combined cycle engine concepts providing extended flight capabilities, i.e. propelling the aircraft from take-off to hypersonic speeds, are proposed to achieve high-speed civil air transportation. STRATOFLY project is a continuation of former European efforts in hypersonic research and aims at developing a commercial reusablevehicle for cruise speed of Mach 8 at stratospheric altitudes as high as 35 km above ground level. The propulsion plant of STRATOFLY aircraft consists of combination of two different type of engines: an array of air turbo rockets and a dualmode ramjet/scramjet. In the present study, 1D transient thermodynamic simulations for this combined cycle propulsion plant have been conducted between Mach 0 to 8 by utilizing 1D inviscid flow transport relations, numerical tools availablein EcosimPro software platform and the European Space Propulsion System Simulation libraries. The optimized engine parameters are achieved by coupling EcosimPro software with Computer Aided Design Optimization which is a differential evolution algorithm developed at the von Karman Institute.

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Колосенок, С. В., А. Л. Куранов, А. А. Саваровский, П. В. Булат, А. А. Галаджун, А. А. Левихин, and А. Б. Никитенко. "Применение вспомогательных топлив для управления сверхзвуковыми потоками реагирующих топливно-воздушных смесей в канале камеры сгорания." Письма в журнал технической физики 47, no. 19 (2021): 19. http://dx.doi.org/10.21883/pjtf.2021.19.51507.18764.

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Besides gas-dynamic methods, chemical ones are also suitable for the implementation of stable supersonic combustion of hydrocarbon fuels. Organoelemental compounds are known for their high reactivity, so attention was paid to organosilicon liquid during the research on the experimental model. The obtained estimates of the laminar flame speed in a mixture of vapors of this liquid with air were 0.72-0.8 m/s, which is higher than that of ethylene successfully used in supersonic combustion tests. The tested compound can be considered as a candidate for supplementary fuel to control the supersonic reactive flows in the combustion chambers of ramjet engines.

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35

Fureby, C. "Large eddy simulation modelling of combustion for propulsion applications." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 367, no. 1899 (July 28, 2009): 2957–69. http://dx.doi.org/10.1098/rsta.2008.0271.

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Predictive modelling of turbulent combustion is important for the development of air-breathing engines, internal combustion engines, furnaces and for power generation. Significant advances in modelling non-reactive turbulent flows are now possible with the development of large eddy simulation (LES), in which the large energetic scales of the flow are resolved on the grid while modelling the effects of the small scales. Here, we discuss the use of combustion LES in predictive modelling of propulsion applications such as gas turbine, ramjet and scramjet engines. The LES models used are described in some detail and are validated against laboratory data—of which results from two cases are presented. These validated LES models are then applied to an annular multi-burner gas turbine combustor and a simplified scramjet combustor, for which some additional experimental data are available. For these cases, good agreement with the available reference data is obtained, and the LES predictions are used to elucidate the flow physics in such devices to further enhance our knowledge of these propulsion systems. Particular attention is focused on the influence of the combustion chemistry, turbulence–chemistry interaction, self-ignition, flame holding burner-to-burner interactions and combustion oscillations.

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Yanovskii, L. S., D. B. Lempert, V. V. Raznoschikov, and I. S. Aver’kov. "Evaluation of Effectiveness of Solid Fuels Based on High Enthalpy Dispersants for Rocket Ramjet Engines." Russian Journal of Applied Chemistry 92, no. 3 (March 2019): 367–88. http://dx.doi.org/10.1134/s1070427219030078.

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37

Magerramova, L. A., Yu A. Nozhnitsky, S. A. Volkov, M. E. Volkov, V. Zh Chepurnov, S. V. Belov, I. S. Verbanov, and S. V. Zaikin. "Prospects of application of additive technologies to develop parts and components of gas turbine engines and ramjets." VESTNIK of Samara University. Aerospace and Mechanical Engineering 18, no. 3 (October 31, 2019): 81–98. http://dx.doi.org/10.18287/2541-7533-2019-18-3-81-98.

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The possibility of reducing the weight, simplifying the design, reducing the time and cost of development, production and operation are important advantages in the implementation of additive technologies (AT). The use of AT can significantly improve fuel efficiency, environmental and other characteristics of aircraft engines. The possibility of using AT in the production of various parts and components of engines is being currently investigated at CIAM. Examples of these developments, advantages of the use of AT and problems arising in the implementation of these technologies are presented in this article. Models of turbine blades with a highly efficient cooling system, in particular, with penetration cooling were designed and manufactured using optimization methods and taking into account the capabilities of AT. The possibilities of using AT for the manufacture of elements of molds for precision casting of gas turbine engine (GTE) blades of heat-resistant alloys and ceramic rods are shown. Elements of a two-zone front module of the low-emission combustion chamber of an advanced GTE are designed and manufactured using the AT method. Research of prospective branched tree channels of heat exchangers with mutually porous bodies that can be made only by AT methods and the use of which will make it possible to increase the efficiency of heat exchange in the case of lower weight, than that of the structures made by traditional technologies, is being carried out. The AT was used to manufacture complex elements of a ramjet engine. Fire tests of printed sections of the combustion chamber were carried out successfully. Cellular structures to be used in gas turbine engine parts with the aim of reducing their weight were developed. A hollow blade model with cellular-type core was made using AT. Tests of the designed cellular prototypes were carried out. The possibilities of reducing the mass of structural elements using cellular structures obtained by AT methods are shown. Research of hollow disks of turbines and other engine components produced with the aid of AT are carried out. Despite the fact that experimental studies of structural elements obtained by additive technologies have not been completed yet, these works show the prospects for the use of AT in the development of a wide range of engine parts and components.

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38

Kolosenok S.V., Kuranov A.L., Savarovskiy A.A., Bulat P.V., Galadzhun A.A., Levihin A.A., and Nikitenko A.B. "The application of supplementary fuels for the control of supersonic reacting air-fuel mix flows in the combustion chamber." Technical Physics Letters 48, no. 13 (2022): 40. http://dx.doi.org/10.21883/tpl.2022.13.53351.18764.

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Besides gas-dynamic methods, chemical ones are also suitable for the implementation of stable supersonic combustion of hydrocarbon fuels. Organoelemental compounds are known for their high reactivity, so attention was paid to organosilicon liquid during the research on the experimental model. The obtained estimates of the laminar flame speed in a mixture of vapors of this liquid with air were 0.72-0.8 m/s, which is higher than that of ethylene successfully used in supersonic combustion tests. The tested compound can be considered as a candidate for supplementary fuel to control the supersonic reactive flows in the combustion chambers of ramjet engines. Keywords: supersonic combustion, supplementary fuels, laminar flame speed, combustion efficiency

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39

Yanovskii, L. S., V. V. Raznoschikov, I. S. Averkov, M. S. Sharov, and D. B. Lempert. "Evaluation of the Performance of Some Metals and Nonmetals in Solid Propellants for Rocket-Ramjet Engines." Combustion, Explosion, and Shock Waves 56, no. 1 (January 2020): 71–82. http://dx.doi.org/10.1134/s0010508220010098.

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40

Xu, Jing, Kunlin Cheng, Chaolei Dang, Yilin Wang, Zekuan Liu, Jiang Qin, and Xiaoyong Liu. "Performance comparison of liquid metal cooling system and regenerative cooling system in supersonic combustion ramjet engines." Energy 275 (July 2023): 127488. http://dx.doi.org/10.1016/j.energy.2023.127488.

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41

Tovkach, Serhii. "Self-tuning Process of the Control Laws of the Aviation Gas Turbine Engine." Electronics and Control Systems 3, no. 73 (November 24, 2022): 27–34. http://dx.doi.org/10.18372/1990-5548.73.17009.

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The article is devoted to the selection of parameters and evaluation of the efficiency of an aviation engine based on a system approach, when the engine and power plant are considered as subsystems of a higher-level aircraft complex. To solve the problems of multiparameter optimization, complex mathematical models of the entire system, consisting of the aircraft and control systems, taking into account the properties of the used fuels, are developed. The integration of the aircraft engine and the aircraft is carried out on the basis of the conditions for ensuring mass balance, the volume layout of the starting thrust-mass ratio. In combined power plants, it is possible to consider engines of different types, for example, TPrE with parallel or sequential (tandem) arrangement of circuits, TRBEaf and ramjet and steam hydrogen rocket-turbine engines of several types, the parameters of the working process of which are optimized according to the conditions of a typical program flights The adaptation task can be solved by changing both control programs and parameters of intellectual regulators of individual subsystems, as well as the structure of individual subsystems and connections between them. The higher level determines which strategy and which adaptation algorithm to choose in this situation. The optimal behavior model of the system in the current situation is also determined here. At the next level (the level of the technological complex), a strategy for the integration of the control and planning systems of the gas station, technological equipment and information system is formed, depending on the modes of operation of the gas station and the fulfillment of the tasks set before it. The construction of the ACS GTE model in the VisSim modeling software package was completed, measures were taken to stabilize the system. The transfer functions of the main elements of the electronic automatic control system of the GTE were obtained: a speed sensor, a thermocouple, and a pressure sensor. sensor of the angular position, the actuator mechanism of the nozzle-valve, the movement of the aircraft by the pitch angle.

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42

Tovstonog, V. A., V. I. Tomak, Az A. Aliev, and A. S. Burkov. "Simulating Thermal State of High-Temperature Ceramic Samples." Herald of the Bauman Moscow State Technical University. Series Natural Sciences, no. 2 (95) (April 2021): 85–101. http://dx.doi.org/10.18698/1812-3368-2021-2-85-101.

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Developing high-velocity atmospheric aircraft equipped with ramjet engines, which use atmospheric air as the oxidizer, is an important component of aerospace technology prospects. These craft may be employed to quickly deliver payloads over intercontinental distances and as boosters for spacecraft injection into orbit. A characteristic feature of high-velocity atmospheric aircraft is a presence of sharp aerofoil edges subjected to highly oxidative airflow. This means that actual implementation of numerous hypersonic atmospheric aircraft projects largely depends on whether it is possible to develop materials that could remain stable in an oxidative atmosphere at temperatures of 2000--2500 °C. We estimated the thermal state of a structural component in the shape of a blunted wedge made out of promising refractory ceramics under flight conditions at an altitude of 22 km and a velocity of Mach 7

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43

Tai, Zhengqi, Qian Chen, Xiaofei Niu, Zhenhua Lin, and Hesen Yang. "Plasma Actuation for the Turbulent Mixing of Fuel Droplets and Oxidant Air in an Aerospace Combustor." Aerospace 10, no. 1 (January 12, 2023): 77. http://dx.doi.org/10.3390/aerospace10010077.

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In order to explore plasma-assisted turbulent mixing in aerospace engines, the dielectric barrier discharge plasma actuation for the turbulent mixing of fuel droplets and oxidant air in a ramjet combustor was studied using computational fluid dynamics. A two-way coupling of turbulent air and discrete droplets was realized by Eulerian–Lagrangian simulation, and the dielectric barrier discharge plasma action on flow was modeled by body force. The results show that the plasma actuation can rearrange the recirculation zone behind the evaporative V-groove flameholder, and the main mechanism of actuation is to increase the local momentum of the fluid; the actuation dimension, actuation intensity, and actuation position of the dielectric barrier discharge plasma have strong effects on the turbulent mixing of fuel droplets and oxidant air; and a relatively optimal turbulent mixing can be achieved by adjusting the actuation parameters.

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44

Huang, Hai-Tao, Mei-Shuai Zou, Xiao-Yan Guo, Rong-Jie Yang, and Peng Zhang. "Analysis of the Solid Combustion Products of a Mg-Based Fuel-Rich Propellant used for Water Ramjet Engines." Propellants, Explosives, Pyrotechnics 37, no. 4 (July 13, 2012): 407–12. http://dx.doi.org/10.1002/prep.201100127.

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45

Baev, V. K., and V. V. Shumskii. "Effect of model dimensions on the thrust characteristics of ramjet engines in tests in a short-duration facility." Combustion, Explosion, and Shock Waves 35, no. 1 (January 1999): 1–7. http://dx.doi.org/10.1007/bf02674378.

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46

Tovstonog, V. A. "Comparative Assessment of Thermal Protective Characteristics of Metal and Ceramic Shields of Flow Paths of High-Temperature Gas Dynamic Facilities." Herald of the Bauman Moscow State Technical University. Series Mechanical Engineering, no. 2 (131) (April 2020): 52–75. http://dx.doi.org/10.18698/0236-3941-2020-2-52-75.

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In modern technology, gas dynamic facilities with a flow path of a high-temperature working fluid are widely used. Their effectiveness largely depends on the maximum achievable temperature, which is to a great extent determined by the heat resistance of structural materials and thermal protection systems of the most heat-stressed structural units. Most often, mass transfer thermal protection methods using the coolant of fuel components are used in such plants. However, in some gas dynamic facilities, such as high-speed ramjet engines, the use of such methods is only sufficient to maintain an acceptable temperature level for the elements of the flow path itself. As for the thermal protection of the enclosing structural elements which are adjacent to the path, it can be provided with either uncooled screens or heat-insulating linings. The study gives a comparative assessment of the temperature regime and characteristics of alternative types of heat shields

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47

Shynkarenko, Olexiy, and Domenico Simone. "Oxygen–Methane Torch Ignition System for Aerospace Applications." Aerospace 7, no. 8 (August 7, 2020): 114. http://dx.doi.org/10.3390/aerospace7080114.

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A new ignition system, based on a CH4/O2 torch has been developed by the Chemical Propulsion Laboratory of the University of Brasilia. Designed to ignite a hybrid rocket, this device has been improved to be used in testing of solid and liquid ramjet engines under development in our lab. The capability to provide multiple ignitions and to cool-down its combustion chamber walls by using a swirled injection of the oxidizer, along with a very low weight to power ratio, makes this device versatile. The igniter is controlled by a feedback system, developed by our group, which guarantees the possibility of operating in different design conditions enabling, therefore, complete integration with systems of different nature. The main characteristics of the igniter and the design solutions are presented including some considerations about the tests performed to evaluate the quality and performance of the ignition system.

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48

Yan, Chenglong, Chen Shu, Jiafeng Zhao, Lingyu Su, Yiheng Tong, Qiaofeng Xie, and Wei Lin. "Influences of thermal physical property parameters on operating characteristics of simulated rotating detonation ramjet fueled by C₁₂H₂₃." AIP Advances 12, no. 11 (November 1, 2022): 115309. http://dx.doi.org/10.1063/5.0101939.

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Two-phase rotating detonation ramjets are considered to be suitable for aerospace applications due to their high thermodynamic cycle efficiency. These engines have an extremely complex internal flow field, in which the liquid fuel undergoes physical and chemical processes such as fragmentation, evaporation, mixing, and combustion; these processes also interact with detonation waves that have significant gradients. This makes it difficult to simulate a three-dimensional (3D) full-process rotating detonation combustion chamber. Here, based on the Euler–Lagrangian simulation method, a 3D numerical combustion chamber was simulated using kinetic theory and the constant thermal physical property parameter (TPPP) calculation method. The accuracy of these methods was then compared with the existing experimental results and theoretical values. Calculating the TPPPs using kinetic theory brought about a relatively high-pressure peak and detonation wave temperature; the detonation wave profile was also finer and more precise. The detonation wave propagation velocity of the two-phase detonation is estimated to be about 60% of the theoretical gas-phase CJ velocity. The calculation method of physical parameters has relatively little influence on the engine’s operating frequency and the detonation wave's propagation velocity but has a more significant influence on the peak pressure. Constant TPPPs can be used when the Kelvin–Helmholtz–Rayleigh–Taylor model with insufficient precision is used to consider the breakup of droplets and leads to the acceleration of the propagation speed of two-phase detonation waves.

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Hong, Z. C., C. C. Lee, and C. J. Tseng. "A Concept of Vertical Takeoff Two-Stage-to-Orbit Reusable Launch Vehicle with an Integral-Rocket-Ramjet Booster." Journal of Mechanics 21, no. 1 (March 2005): 51–56. http://dx.doi.org/10.1017/s172771910000054x.

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AbstractReusable launch vehicles (RLV) currently envisioned incorporate a wide variety of propulsion types. Various propulsion devices have been designed, or are being designed. The Integral-Rocket-Ramjet (IRR) propulsion mainly applies to a tactical missile boost system and few have mentioned this system in RLV design. According to the technological ability of Taiwan and a feasibility study, it shows that the present reusable launch system can exploit the potential benefit of IRR propulsion for the RLV system. A conceptual study of an unmanned two-stage-to-orbit (TSTO) launch vehicle is designed in this paper. The first stage of the vehicle is reusable with IRR engines. The second stage is expendable and rocket powered. The assumed mission is designed to insert a 100kg payload into a low earth circular orbit at various inclination angles. The calculations are made for the case where the TSTO system is used in Taiwan. The fundamentals of launch vehicle design are examined using simplified two-stage performance equations. Launch vehicle design is optimized when the performance and programmatic drivers are balanced. There is an acceptable set of launch and landing sites on islands off the coast of Taiwan.

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Bordoloi, Namrata, Krishna Murari Pandey, and Kaushal Kumar Sharma. "Numerical Investigation on the Effect of Inflow Mach Numbers on the Combustion Characteristics of a Typical Cavity-Based Supersonic Combustor." Mathematical Problems in Engineering 2021 (September 8, 2021): 1–14. http://dx.doi.org/10.1155/2021/3526454.

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The air-breathing engines, commonly known as Supersonic Combustor Ramjet (SCRAMJET) engines, are one of the most prominent technologies among researchers due to their high thrust-to-weight ratio. The researchers are constantly making efforts for improved performance of the combustor under the required boundary conditions. The present working computational model studies a hydrogen-fueled parallel cavity scramjet combustor to recognize the complex flow field characteristics and performance of the combustor in Ansys 15.0. The computational model developed is a replica of an experiment conducted in China which slightly modified the boundary conditions. The standard two-equation K- ε turbulence model and Reynolds averaged Navier Stokes (RANS) equation with finite-rate/eddy dissipation species reaction model are used to simulate the problem. The validation of the present model is achieved by comparing the results with already available experimental data in conformity with the literature. The results of the simulations are in satisfactory accord with the experimental data and images. Furthermore, to achieve the stated objective, different incoming Mach numbers, namely, 2.25, 2.52, and 2.75, are considered for a more clear understanding of variables that affects the characteristics of the flow field. The temperature, Mach number, density pressure, and H2O mass fraction contours were studied to facilitate proper understanding. The maximum temperature rise observed is 2711.467 K for M = 2.25. Additionally, the performance parameters, namely, combustion and mixing efficiencies, are also studied. The maximum combustion and mixing efficiencies are 87.47% and 98.15% for M = 2.25 and 2.75, respectively.

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Journal articles on the topic 'Ramjet engines'

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