Download or read book Investigation of Air Augmented Rocket Combustion and Mixing Processes written by W. H. Sargent and published by . This book was released on 1967 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt: Data on coaxial jet mixing and combustion developed during a ten-week test program are presented along with a limited analysis of results. The test was conducted with a rocket motor simulator which generated a fuel-rich primary stream. The combustion of the primary stream was varied systematically through a broad range of conditions, and the exchange processes were observed in a secondary mixing duct by means of wall pressure measurements, thrust measurements, and measurements of heat flux. Photographic observations were made of the primary stream operating as a free jet. Preliminary analysis indicates that the length of duct required for momentum and energy exchange to occur depends primarily upon the secondary air mass flow. A brief discussion is included on the grouping of variables in afterburning problems, and a simplified 'throttling number' parameter is suggested. Also included are the results of a mixing zone computation in which the differential equations of coaxial mixing are solved by a finite difference procedure. Results are presented of calculations made to predict wall pressure profiles that are influenced by the presence of the bluff face of the primary stream blast tube. This analysis covers the flow regime that extends to the length of the primary stream potential core. (Author).
Download or read book Proceedings written by and published by . This book was released on 1968 with total page 614 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technical Abstract Bulletin written by and published by . This book was released on with total page 818 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Air Augmented Rocket Fixed Fuel Flow Combustion Characterization Program written by Jerry L. Fields and published by . This book was released on 1973 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: This program demonstrated that reliable, consistent combustion efficiency data could be obtained independently at different facilities. The detailed combustion efficiency performance of two Boron loaded fuel rich propellants was mapped over an air-to-fuel ratio range from 10 to 40 and a ramburner air-only pressure range from 13 to 40 psia. Two highly loaded Boron propellants were used. Testing was conducted at three facilities. Six inch subscale hardware was utilized and a coaxial mixing configuration chosen. Data analysis procedures were refined and error sources (particularly fuel flow rate uncertainties) minimized. The averaged combustion efficiency data from all three facilities fell within the computed error bands, + or - 5.5 percent. Significant A/F dependence was found for combustion efficiency for the two propellants. The effect of fuel generator pressure on combustion efficiency was briefly investigated and found to be negligible. Finally, a propellant comparison was made and ARC 256A had generally better combustion efficiency performance and a higher theoretical heating value, leading to its selection as the superior propellant. (Author).
Download or read book Performance of air augmented rockets written by David J. Rickeard and published by . This book was released on 1973 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the Fifth AFOSR Symposium on Advanced Propulsion Concepts written by and published by . This book was released on 1970 with total page 614 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Study of Mixing and Combustion Processes in a Solid propellant Ducted Rocket Motor written by Chin-Lung Chuang and published by . This book was released on 1989 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Investigation of Ramburner Performance Part I Liquid Propellant Runs written by R. A. Meese and published by . This book was released on 1972 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes the results of a series of connected-pipe runs with an air-augmented rocket system burning liquid rocket propellants. The liquid propellant runs served to evaluate the behavior of the facility and instrumentation with regard to accuracy and to provide performance data for combustion where the chemical rate processes were relatively fast compared with those of metal combustion. The ramburner was designed to provide axisymmetric, coaxial mixing of the primary and secondary streams in a constant area duct. No mixing aids were employed. Nitrogen tetroxide and Aerozine-50 served as the rocket propellants. The secondary air was preheated by combustion to a nominal temperature of 1100 R to simulate flight stagnation conditions. Runs were made with nominal pressures in the ramburner of 90 and 175 psia. The air/propellant ratio was varied from 5 to 13 (approximately 250 to 600 percent theoretical air). Two oxidizer-to-fuel ratios were employed for the primary rocket: 0.8 (fuel rich) and 2.0 (stoichiometric). Combustion efficiencies between 75 and 90 percent were observed for the complete system, decreasing with increasing air/propellant ratio. Estimated uncertainties in the efficiency values were + or - 3 percent. Ramburner efficiencies tended to be 10 to 15 percent lower and were subject to uncertainties in the neighborhood of + or - 6 percent. A slight decrease in efficiency with decreasing pressure was also observed. (Author).
Download or read book An Inventory of Energy Research written by Oak Ridge National Laboratory and published by . This book was released on 1972 with total page 1136 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of a Numerical Tool to Study the Mixing Phenomenon Occuring During Mode One Operation of a Multi mode Ejector augmented Plused Detonation Rocket Engine written by Joshua Dawson and published by . This book was released on 2016 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: A novel multi-mode implementation of a pulsed detonation engine, put forth by Wilson et al. [2], consists of four modes; each specifically designed to capitalize on flow features unique to the various flow regimes. This design enables the propulsion system to generate thrust through the entire flow regime. The multi-mode ejectoraugmented pulsed detonation rocket engine operates in mode one during take-o_ conditions through the acceleration to supersonic speeds. Once the mixing chamber internal flow exceeds supersonic speed, the propulsion system transitions to mode two. While operating in mode two, supersonic air is compressed in the mixing chamber by an upstream propagating detonation wave and then exhausted through the convergent-divergent nozzle. Once the velocity of the air flow within the mixing chamber exceeds the Chapman-Jouguet Mach number, the upstream propagating detonation wave no longer has sufficient energy to propagate upstream and consequently the propulsive system shifts to mode three. As a result of the inability of the detonation wave to propagate upstream, a steady oblique shock system is established just upstream of the convergent-divergent nozzle to initiate combustion. And finally, the propulsion system progresses on to mode four operation, consisting purely of a pulsed detonation rocket for high Mach number flight and use in the upper atmosphere as is needed for orbital insertion. Modes three and four appear to be a fairly significant challenge to implement, while the challenge of implementing modes one and two may prove to be a more practical goal in the near future. A vast number of potential applications exist for a propulsion system that would utilize modes one and two, namely a high Mach number hypersonic cruise vehicle. There is particular interest in the dynamics of mode one operation, which is the subject of this study. Several advantages can be obtained by use of this technology. Geometrically, the propulsion system is fairly simple and the rapid combustion process results in an engine cycle which is more efficient compared to its combined-cycle counterparts. The flow path geometry consists of an inlet system, followed just downstream by a mixing chamber where an ejector structure is placed within the flow path. Downstream of the ejector structure is a duct leading to a convergent-divergent nozzle. During mode one operation and within the ejector, products from the detonation of a stoichiometric hydrogen/air mixture are exhausted directly into the surrounding secondary air stream. Mixing then occurs between both the primary and secondary flow streams, at which point the air mass containing the high pressure, high temperature reaction products is convected downstream towards the nozzle. The engine cycle is engineered to a specific number of detonations per second, creating the pulsating characteristic of the primary flow. The pulsing nature of the primary flow serves as a momentum augmentation, enhancing the thrust and specific impulse at low speeds. Consequently, it is necessary to understand the transient mixing process between the primary and secondary flow streams occurring during mode one operation. Using OPENFOAM®, a numerical tool is developed to simulate the dynamics of the turbulent detonation process along with detailed chemistry in order to understand the physics involved with the stream interactions. The computational code has been developed within the framework of OPENFOAM®, an open-source alternative to commercial CFD software. A conservative formulation of the Farve averaged Navier-Stokes equations are used to facilitate programming and numerical stability. Time discretization is accomplished by using the Crank-Nicolson method, achieving second-order convergence in time. Species mass fraction transport equations are implemented and a Seulex ODE solver was used to resolve the system of ordinary differential equations describing the hydrogen-air reaction mechanism detailed in Appendix A. The Seulex ODE solution algorithm is an extrapolation method based on the linearly implicit Euler method with step size control. A second-order total variation diminishing method with a modified Sweby ux limiter was used for space discretization. And finally the use of operator splitting (PISO algorithm, and chemical kinetics) is essential due to the significant differences in characteristic time scales evolving simultaneously in turbulent reactive flow. Capturing the turbulent nature of the combustion process was done using the k-w-SST turbulence model, as formulated by, [1]. Mentor's formulation is well suited to resolve the boundary layer while remaining relatively insensitive to freestream conditions, blending the merits of both the k-w and k-E models. Further developement of the tool is possible, most notably with the Numerical Propulsion System Simulation application. NPSS allows the user to take advantage of a zooming functionality in which high-fidelity models of engine components can be integrated into NPSS models, allowing for a more robust propulsion system simulation. A more comprehensive understanding of the multi-mode ejector-augmented pulsed detonation rocket engine can be achieved with a systematic study of the impact pulsed flow has on thrust production. Although a significant increase in computational requirements, adding nozzle geometry to this study would illuminate any problems associated with pulsed flow through a nozzle. Additionally, a study including nozzle geometry would bring more clarity in regards to the efficiency of the propulsion design.
Download or read book Fundamentals of Rocket Propulsion written by DP Mishra and published by CRC Press. This book was released on 2017-07-20 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book follows a unified approach to present the basic principles of rocket propulsion in concise and lucid form. This textbook comprises of ten chapters ranging from brief introduction and elements of rocket propulsion, aerothermodynamics to solid, liquid and hybrid propellant rocket engines with chapter on electrical propulsion. Worked out examples are also provided at the end of chapter for understanding uncertainty analysis. This book is designed and developed as an introductory text on the fundamental aspects of rocket propulsion for both undergraduate and graduate students. It is also aimed towards practicing engineers in the field of space engineering. This comprehensive guide also provides adequate problems for audience to understand intricate aspects of rocket propulsion enabling them to design and develop rocket engines for peaceful purposes.
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1974 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Inventory of Energy Research Prepared for the Task Force on Energy of the Subcommittee on Science Research and Development by Oak Ridge National Laboratory with the Support of the National Science Foundation written by United States. Congress. House. Science and Astronautics and published by . This book was released on 1972 with total page 1124 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings written by and published by . This book was released on 1969 with total page 614 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book pt III and IV written by Oak Ridge National Laboratory and published by . This book was released on 1974 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Air Force Research Resum s written by and published by . This book was released on with total page 854 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book FY US Air Force Plan for Defense Research Sciences written by and published by . This book was released on 1984 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
