Download or read book Acoustically Excited Heated Jets 2 written by J. Lepicovsky and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The second part of a three-part report on the effects of acoustic excitation on jet mixing includes the results of an experimental investigation directed at resolving the question of poor excitability of some of the heated jets. The theoretical predictions discussed in Part 1 are examined to find explanations for the observed discrepancies between the measured and the predicted results. Additional testing was performed by studying the self excitation of the shock containing hot jets and also by exciting the jet by sound radiated through source tubes located externally around the periphery of the jet. The effects of nozzle-exit boundary layer conditions on jet excitability was also investigated. It is concluded that high-speed, heated jet mixing rates and consequently also the jet excitability strongly depends on nozzle exit boundary layer conditions.
Download or read book Acoustically Excited Heated Jets 2 In Search of a Better Understanding written by and published by . This book was released on 1988 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acoustically Excited Heated Jets written by and published by . This book was released on 1988 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acoustically Excited Heated Jets 1 Internal Excitation written by and published by . This book was released on 1988 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of relatively strong upstream acoustic excitation on the mixing of heated jets with the surrounding air are investigated. To determine the extent of the available information on experiments and theories dealing with acoustically excited heated jets, an extensive literature survey was carried out. The experimental program consisted of flow visualization and flowfield velocity and temperature measurements for a broad range of jet operating and flow excitation conditions. A 50.8-mm-diam nozzle was used for this purpose. Parallel to the experimental study, an existing theoretical model of excited jets was refined to include the region downstream of the jet potential core. Excellent agreement was found between theory and experiment in moderately heated jets. However, the theory has not yet been confirmed for highly heated jets. It was found that the sensitivity of heated jets to upstream acoustic excitation varies strongly with the jet operating conditions and that the threshold excitation level increases with increasing jet temperature. Furthermore, the preferential Strouhal number is found not to change significantly with a change of the jet operating conditions. Finally, the effects of the nozzle exit boundary layer thickness appear to be similar for both heated and unheated jets at low Mach numbers.
Download or read book Acoustically Excited Heated Jets written by and published by . This book was released on 1988 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acoustically Excited Heated Jets 3 written by and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This is Part 3 of a report on the excitability of heated jets under the influence of acoustic excitation. The effects of upstream internal acoustic excitation on jet mixing were described in Part 1. Part 2 described the effects of external excitation on flow mixing. Part 3 contains quantitative results from the measurements of mean Mach number and temperature and consists of radial profiles and centerline distributions measured at selected jet operating conditions for internally excited and unexcited jets. The mean flow data are presented in both graphical and tabulated forms. For the sake of completeness, this part contains temperature probe calibration curves also.
Download or read book Acoustically Excited Heated Jets 3 written by National Aeronautics and Space Adm Nasa and published by . This book was released on 2018-11-10 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is Part 3 of a report on the excitability of heated jets under the influence of acoustic excitation. The effects of upstream internal acoustic excitation on jet mixing were described in Part 1. Part 2 described the effects of external excitation on flow mixing. Part 3 contains quantitative results from the measurements of mean Mach number and temperature and consists of radial profiles and centerline distributions measured at selected jet operating conditions for internally excited and unexcited jets. The mean flow data are presented in both graphical and tabulated forms. For the sake of completeness, this part contains temperature probe calibration curves also. Lepicovsky, J. and Ahuja, K. K. and Brown, W. H. and Salikuddin, M. and Morris, P. J. Unspecified Center ACOUSTIC EXCITATION; FLOW VISUALIZATION; JET MIXING FLOW; FLOW DISTRIBUTION; FLOW VELOCITY; GRAPHS (CHARTS); JET FLOW; MACH NUMBER; TABLES (DATA)...
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1988 with total page 968 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acoustically Excited Heated Jets 3 Mean Flow Data written by and published by . This book was released on 1988 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scramjets written by Mostafa Barzegar Gerdroodbary and published by Butterworth-Heinemann. This book was released on 2020-07-21 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scramjet engines are a type of jet engine and rely on the combustion of fuel and an oxidizer to produce thrust. While scramjets are conceptually simple, actual implementation is limited by extreme technical challenges. Hypersonic flight within the atmosphere generates immense drag, and temperatures found on the aircraft and within the engine can be much greater than that of the surrounding air. Maintaining combustion in the supersonic flow presents additional challenges, as the fuel must be injected, mixed, ignited, and burned within milliseconds. Fuel mixing, along with the configuration and positioning of the injectors and the boundary conditions, play a key role in combustion efficiency. Scramjets: Fuel Mixing and Injection Systems discusses how fuel mixing efficiency and the advantage of injection systems can enhance the performance of the scramjets. The book begins with the introduction of the supersonic combustion chamber and explains the main parameters on the mixing rate. The configuration of scramjets is then introduced with special emphasis on the main effective parameters on the mixing of fuel inside the scramjets. In addition, basic concepts and principles on the mixing rate and fuel distribution within scramjets are presented. Main effective parameters such as range of fuel concentration for the efficient combustion, pressure of fuel jet and various arrangement of jet injections are also explained. This book is for aeronautical and mechanical engineers as well as those working in supersonic combustion who need to know the effects of compressibility on combustion, of shocks on mixing and on chemical reactions, and vorticity on the flame anchoring. Explains the main applicable approaches for enhancement of supersonic combustion engines and the new techniques of fuel injection Shows how the interaction of main air stream with fuel injections can develop the mixing inside the scramjets Presents results of numerical simulations and how they can be used for the development of the combustion engines
Download or read book Investigation of Synthetic Jets Heat Transfer and Flow Field written by Carlo Salvatore Greco and published by Youcanprint. This book was released on 2015-04-30 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt: Synthetic jets are devices able to “synthetize” a jet from the ambient in which they are embedded through a simple membrane oscillation inside a cavity with an orifice. Such features make them high reliable, silent and easy to be miniaturized. For these reasons, they are widely investigated as electronic cooling devices. The present research is focused on the design and analysis of a different type of synthetic jet device compared to its single classical configuration. Such a device his experimentally characterized through the study of its free and impinging flow field and the evaluation of its heat transfer performance.
Download or read book Acoustic Control of Turbulent Jets written by A.S. Ginevsky and published by Springer Science & Business Media. This book was released on 2012-11-02 with total page 243 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results of experimental research on aerodynamic and acoustic control of subsonic turbulent jets by acoustic excitation are presented. It was demonstrated that these control methods, originated by authors, not only can intensify mixing (by acoustic irradiation at low frequency), but also notably ease it (at high-frequency irradiation). This research monograph presents the updated results of the authors supplemented by other investigations conducted in USA, Germany and Great Britain. The methods for the numerical simulation of subsonic turbulent jets under acoustic excitation are described in detail, and examples are reviewed of practical applications, including reduction of turbojet engine noise and acoustic control of self-sustained oscillations in wind tunnels.
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1974 with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Use of Services for Family Planning and Infertility United States 1982 written by Gerry E. Hendershot and published by . This book was released on 1988 with total page 982 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 1982 statistics on the use of family planning and infertility services presented in this report are preliminary results from Cycle III of the National Survey of Family Growth (NSFG), conducted by the National Center for Health Statistics. Data were collected through personal interviews with a multistage area probability sample of 7969 women aged 15-44. A detailed series of questions was asked to obtain relatively complete estimates of the extent and type of family planning services received. Statistics on family planning services are limited to women who were able to conceive 3 years before the interview date. Overall, 79% of currently mrried nonsterile women reported using some type of family planning service during the previous 3 years. There were no statistically significant differences between white (79%), black (75%) or Hispanic (77%) wives, or between the 2 income groups. The 1982 survey questions were more comprehensive than those of earlier cycles of the survey. The annual rate of visits for family planning services in 1982 was 1077 visits /1000 women. Teenagers had the highest annual visit rate (1581/1000) of any age group for all sources of family planning services combined. Visit rates declined sharply with age from 1447 at ages 15-24 to 479 at ages 35-44. Similar declines with age also were found in the visit rates for white and black women separately. Nevertheless, the annual visit rate for black women (1334/1000) was significantly higher than that for white women (1033). The highest overall visit rate was for black women 15-19 years of age (1867/1000). Nearly 2/3 of all family planning visits were to private medical sources. Teenagers of all races had higher family planning service visit rates to clinics than to private medical sources, as did black women age 15-24. White women age 20 and older had higher visit rates to private medical services than to clinics. Never married women had higher visit rates to clinics than currently or formerly married women. Data were also collected in 1982 on use of medical services for infertility by women who had difficulty in conceiving or carrying a pregnancy to term. About 1 million ever married women had 1 or more infertility visits in the 12 months before the interview. During the 3 years before interview, about 1.9 million women had infertility visits. For all ever married women, as well as for white and black women separately, infertility services were more likely to be secured from private medical sources than from clinics. The survey design, reliability of the estimates and the terms used are explained in the technical notes.
Download or read book AIAA Shear Flow Conference written by and published by . This book was released on 1993 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Annual Index written by and published by . This book was released on 1988 with total page 1084 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 90 3994 to 90 4033 written by and published by . This book was released on 1990 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt:
