Download or read book PIV Measurements of Supersonic Internally mixed Dual stream Jets written by James E. Bridges and published by . This book was released on 2012 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Piv Measurements of Supersonic Internally Mixed Dual Stream Jets written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-05-22 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: While externally mixed, or separate flow, nozzle systems are most common in high bypass-ratio aircraft, they are not as attractive for use in lower bypass-ratio systems and on aircraft that will fly supersonically. The noise of such propulsion systems is also dominated by jet noise, making the study and noise reduction of these exhaust systems very important, both for military aircraft and future civilian supersonic aircraft. This paper presents particle image velocimetry of internally mixed nozzle with different area ratios between core and bypass, and nozzles that are ideally expanded and convergent. Such configurations independently control the geometry of the internal mixing layer and of the external shock structure. These allow exploration of the impact of shocks on the turbulent mixing layers, the impact of bypass ratio on broadband shock noise and mixing noise, and the impact of temperature on the turbulent flow field. At the 2009 AIAA/CEAS Aeroacoustics Conference the authors presented data and analysis from a series of tests that looked at the acoustics of supersonic jets from internally mixed nozzles. In that paper the broadband shock and mixing noise components of the jet noise were independently manipulated by holding Mach number constant while varying bypass ratio and jet temperature. Significant portions of that analysis was predicated on assumptions regarding the flow fields of these jets, both shock structure and turbulence. In this paper we add to that analysis by presenting particle image velocimetry measurements of the flow fields of many of those jets. In addition, the turbulent velocity data documented here will be very useful for validation of computational flow codes that are being developed to design advanced nozzles for future aircraft. Bridges, James E. and Wernet, Mark P. Glenn Research Center PARTICLE IMAGE VELOCIMETRY; SUPERSONIC JET FLOW; AIRPORTS; AIRCRAFT NOISE; SUPERSONIC AIRCRAFT; AEROACOUSTICS; DIRECTIVITY; FAR FIELDS; NOISE REDUCTION; NOZZLE FLOW; CONVERGENT-DIVERGENT NOZZLES; BYPASS RATIO; FLOW DISTRIBUTION
Download or read book Piv Measurements of Supersonic Internally Mixed Dual Stream Jets written by Nasa Technical Reports Server (Ntrs) and published by BiblioGov. This book was released on 2013-06 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: While externally mixed, or separate flow, nozzle systems are most common in high bypass-ratio aircraft, they are not as attractive for use in lower bypass-ratio systems and on aircraft that will fly supersonically. The noise of such propulsion systems is also dominated by jet noise, making the study and noise reduction of these exhaust systems very important, both for military aircraft and future civilian supersonic aircraft. This paper presents particle image velocimetry of internally mixed nozzle with different area ratios between core and bypass, and nozzles that are ideally expanded and convergent. Such configurations independently control the geometry of the internal mixing layer and of the external shock structure. These allow exploration of the impact of shocks on the turbulent mixing layers, the impact of bypass ratio on broadband shock noise and mixing noise, and the impact of temperature on the turbulent flow field. At the 2009 AIAA/CEAS Aeroacoustics Conference the authors presented data and analysis from a series of tests that looked at the acoustics of supersonic jets from internally mixed nozzles. In that paper the broadband shock and mixing noise components of the jet noise were independently manipulated by holding Mach number constant while varying bypass ratio and jet temperature. Significant portions of that analysis was predicated on assumptions regarding the flow fields of these jets, both shock structure and turbulence. In this paper we add to that analysis by presenting particle image velocimetry measurements of the flow fields of many of those jets. In addition, the turbulent velocity data documented here will be very useful for validation of computational flow codes that are being developed to design advanced nozzles for future aircraft.
Download or read book Cross Stream Piv Measurements of Jets with Internal Lobed Mixers written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-21 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: With emphasis being placed on enhanced mixing of jet plumes for noise reduction and on predictions of jet noise based upon turbulent kinetic energy, unsteady measurements of jet plumes are a very important part of jet noise studies. Given that hot flows are of most practical interest, optical techniques such as Particle Image Velocimetry (PIV) are applicable. When the flow has strong azimuthal features, such as those generated by chevrons or lobed mixers, traditional PIV, which aligns the measurement plane parallel to the dominant flow direction is very inefficient, requiring many planes of data to be acquired and stacked up to produce the desired flow cross-sections. This paper presents PIV data acquired in a plane normal to the jet axis, directly measuring the cross-stream gradients and features of an internally mixed nozzle operating at aircraft engine flow conditions. These nozzle systems included variations in lobed mixer penetration, lobe count, lobe scalloping, and nozzle length. Several cases validating the accuracy of the PIV data are examined along with examples of its use in answering questions about the jet noise generation processes in these nozzles. Of most interest is the relationship of low frequency aft-directed noise with turbulence kinetic energy and mean velocity. Bridges, James and Wernet, Mark P. Glenn Research Center NASA/TM-2004-213106, AIAA Paper 2004-2896, E-14581
Download or read book Cross Stream Piv Measurements of Jets with Internal Lobed Mixers written by James Bridges and published by BiblioGov. This book was released on 2013-06 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: With emphasis being placed on enhanced mixing of jet plumes for noise reduction and on predictions of jet noise based upon turbulent kinetic energy, unsteady measurements of jet plumes are a very important part of jet noise studies. Given that hot flows are of most practical interest, optical techniques such as Particle Image Velocimetry (PIV) are applicable. When the flow has strong azimuthal features, such as those generated by chevrons or lobed mixers, traditional PIV, which aligns the measurement plane parallel to the dominant flow direction is very inefficient, requiring many planes of data to be acquired and stacked up to produce the desired flow cross-sections. This paper presents PIV data acquired in a plane normal to the jet axis, directly measuring the cross-stream gradients and features of an internally mixed nozzle operating at aircraft engine flow conditions. These nozzle systems included variations in lobed mixer penetration, lobe count, lobe scalloping, and nozzle length. Several cases validating the accuracy of the PIV data are examined along with examples of its use in answering questions about the jet noise generation processes in these nozzles. Of most interest is the relationship of low frequency aft-directed noise with turbulence kinetic energy and mean velocity.
Download or read book Supersonic PIV Measurements in an Open Jet Flow written by N. Hamel and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Combustion Measurements written by Norman Chigier and published by CRC Press. This book was released on 1991-04-01 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book begins with an introduction to the general problems of making measurements in high temperature and a presentation of chemically reacting flow systems. It describes each instrument with the various diagnostic techniques and discusses measurements that have been made in furnaces, flames, and rocket engines. The detailed measurement techniques described in this book cover a wide spectrum of applications in combustion systems, including gas turbine, rocket measurement techniques that were developed in laboratories. Information obtained on detailed temperature, velocity, particle size, and gas concentration distribution is leading to improve understanding of the chemical combustion process and to design imporvements in combustors.
Download or read book High Resolution Measurements of Supersonic Mixing and Combustion in Coflowing Turbulent Jets written by and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental study of compressibility effects on the large scale structure and outer variable scaling laws of a coflowing turbulent jet was partially completed. Results showed distinct large scale structure and classical incompressible scaling where the convective Mach number has decreased to subsonic values. At supersonic convective Mach numbers no large scale structure was seen and incompressible scalings were dramatically modified. Experiments also showed strong effects due to oblique shock wave interactions with combustion in supersonic turbulent jets. OH PLIF imaging measurements comparing subsonic and supersonic jets documented striking differences in their mixing and combustion properties. Combined OH/CH PLIF imaging measurements found large differences in the combustion properties of jet flames created by small differences in the fuel injection design. A theoretical study of density effects due to combustion heat release on the outer variable scalings of turbulent shear flows was completed. This study produced a general methodology for predicting the changes in such quantities as growth rates, velocity decay, and entrainment and mixing rates due to heat release. Comparisons with measured heat release effects in the literature, including planar and axisymmetric jet flames as well as mixing layers, showed excellent agreement with this general approach.
Download or read book Mixing Measurements of Transverse and Oblique Sonic Jets in Supersonic Cross Flow written by James E. Fay and published by . This book was released on 2006 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Supersonic Cascade Studies Part Ii mixing of Supersonic Jets written by ANDREW A. FEJER and published by . This book was released on 1961 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt: The mixing of 2 supersonic streams was investigated experimentally in a rectangular channel of 4.5:1 length to height ratio. The primary stream was introduced into the passage at M=2.35 while the Mach Number of the secondary stream was varied from 1.45 to 2.20. Changes in the ratio of primary to secondary mass flow-rate were also made. As the 2 streams would be considered completely mixed if the average total pressure of the secondary stream and of the primary stream were to become equal, the total pressure differential between the two streams can be used as a measure of the degree of mixing. The excess of primary total pressure at the passage exit was approximately 40% of the initial total pressure difference and it was observed that this excess was not influenced by changes in secondary Mach Number. It was concluded that passages of substantially greater length to height ratio are required if the momentum of the secondary and primary streams are to become approximately the same. (Author).
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 974 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Particle Image Velocimetry written by Ronald J. Adrian and published by Cambridge University Press. This book was released on 2011 with total page 585 pages. Available in PDF, EPUB and Kindle. Book excerpt: Particle image velocimetry, or PIV, refers to a class of methods used in experimental fluid mechanics to determine instantaneous fields of the vector velocity by measuring the displacements of numerous fine particles that accurately follow the motion of the fluid. Although the concept of measuring particle displacements is simple in essence, the factors that need to be addressed to design and implement PIV systems that achieve reliable, accurate, and fast measurements and to interpret the results are surprisingly numerous. The aim of this book is to analyze and explain them comprehensively.
Download or read book Jet in Supersonic Crossflow written by Mingbo Sun and published by . This book was released on 2019 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: Based on research into jets in supersonic crossflow carried out by the authors’ team over the past 15 years, this book summarizes and presents many cutting-edge findings and analyses on this subject. It tackles the complicated mixing process of gas jets and atomization process of liquid jets in supersonic crossflow, and studies their physical mechanisms. Advanced experimental and numerical techniques are applied to further readers’ understanding of atomization, mixing, and combustion of fuel jets in supersonic crossflow, which can promote superior fuel injection design in scramjet engines. The book offers a valuable reference guide for all researchers and engineers working on the design of scramjet engines, and will also benefit graduate students majoring in aeronautical and aerospace engineering.
Download or read book 15th AIAA Aeroacoustics Conference 93 4320 93 4354 written by and published by . This book was released on 1993 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Shock Wave Boundary Layer Interactions written by Holger Babinsky and published by Cambridge University Press. This book was released on 2011-09-12 with total page 481 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shock wave-boundary-layer interaction (SBLI) is a fundamental phenomenon in gas dynamics that is observed in many practical situations, ranging from transonic aircraft wings to hypersonic vehicles and engines. SBLIs have the potential to pose serious problems in a flowfield; hence they often prove to be a critical - or even design limiting - issue for many aerospace applications. This is the first book devoted solely to a comprehensive, state-of-the-art explanation of this phenomenon. It includes a description of the basic fluid mechanics of SBLIs plus contributions from leading international experts who share their insight into their physics and the impact they have in practical flow situations. This book is for practitioners and graduate students in aerodynamics who wish to familiarize themselves with all aspects of SBLI flows. It is a valuable resource for specialists because it compiles experimental, computational and theoretical knowledge in one place.
Download or read book NASA Technical Memorandum written by and published by . This book was released on 1994 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt:
