Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
An Experimental Study Of The Effect Of Streamwise Vorticity On Supersonic Mixing Enhancement
Download An Experimental Study Of The Effect Of Streamwise Vorticity On Supersonic Mixing Enhancement full books in PDF, epub, and Kindle. Read online An Experimental Study Of The Effect Of Streamwise Vorticity On Supersonic Mixing Enhancement ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis An Experimental Study of the Effect of Streamwise Vorticity on Supersonic Mixing Enhancement by : J. W. Naughton
Download or read book An Experimental Study of the Effect of Streamwise Vorticity on Supersonic Mixing Enhancement written by J. W. Naughton and published by . This book was released on 1989 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Analytical and Experimental Studies on Mixing in Supersonic Flows by : Vijay Gopal
Download or read book Analytical and Experimental Studies on Mixing in Supersonic Flows written by Vijay Gopal and published by . This book was released on 2021 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mixing enhancement in supersonic flow is an important domain of research for enabling the realization of efficient and scalable high speed air-breathing engines (scramjet).Introducing streamwise vorticies in supersonic flow and tailoring their interactions for mixing enhancement is the primary motivation for the present research study. Leveraging the research performed in the group at the Aerodynamics Research Center (ARC), systematic experimental studies on mixing enhancement is carried out in supersonic flows by tailoring the selected modes of stream wise vortex interactions with the aid of in-house developed reduced order method VorTX. This method utilizes the lifting line-vortex theory in supersonic flow to perform rapid simulations of streamwise vortex-interactions that serves as a guide to design the mixing experiments. One of the difficulties associated with scaling the simulations to higher Mach numbers (M > 4) arise from the strong influence of the singularities along the Mach cones emanating from the lifting line-vortex that results in physically inconsistent solution. In this work a fundamental study on vorticity distribution in linearized supersonic flow is carried out. The origin of the aforementioned singularities on the Mach cone is discussed in detail, and the potential candidates for vorticity distribution are proposed to eliminate the singularities and to provide a physically consistent solution of the flow field in supersonic flow. This study presents the successful solution for the elimination of the singularities that has allowed to extend the capability of VorTX to simulate vortex-interactions at higher Mach numbers. Experimental studies on supersonic mixing were carried out using a strut injection platform with vortex generating ramps to introduce streamwise voriticies in supersonic flow. The geometrical configuration of the ramps are chosen using the upgraded VorTX simulations to target the experimental study of two selected modes of vortex interactions. One is the merging of two co-rotating vorticies and the other is the non-merging case where the vorticies interact but do not merge. Mixing measurements in supersonic flow were carried out using the Filtered Rayleigh Scattering (FRS)technique. The measurement yields the mole-fraction of helium (injectant) in a binary mixture of air and helium in supersonic flow. The distributions of helium mole-fraction in the cross flow planes are used to draw conclusions on the level of mixing in the two modes of vortex-interaction. The FRS technique requires two independent experiments. One with helium injection in supersonic air flow and the other with air injection in an identical supersonic air flow. At a given cross-flow plane, to obtain the helium mole-fraction distribution using the FRS signals it is assumed that the total number density is matched in both the experiments. To enhance the reliability of the FRS measurement technique, it is important to minimize and quantify the systematic errors that arise from the assumptions made, particularly, the assumption on matching the total number density. In this work, a method to reduce the systematic errors in FRS experiments is proposed for a canonical case study of a rectangular jet in supersonic flow. To do this, a reduced order model for a rectangular jet in supersonic air flow is successfully developed in order to guide the selection of appropriate injector's plenum conditions to minimize the systematic errors in the future FRS experiments and to retrospectively evaluate and correct the FRS measurements for systematic errors in previously available FRS data on parallel strut injection in supersonic flow.
Author :National Aeronautics and Space Administration (NASA) Publisher :Createspace Independent Publishing Platform ISBN 13 :9781722791841 Total Pages :54 pages Book Rating :4.7/5 (918 download)
Book Synopsis Supersonic Mixing Enhancement by Vorticity for High-Speed Propulsion by : National Aeronautics and Space Administration (NASA)
Download or read book Supersonic Mixing Enhancement by Vorticity for High-Speed Propulsion written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-16 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: The results of a three year study on vortex enhancement of supersonic mixing are discussed. Recent interests in compressible mixing has spurred research in the field of high speed shear layers. It was established that shear layer growth diminishes with increasing convective Mach number; this Mach number is the relative Mach number of the large scale structures in the shear layer with respect to the Mach numbers on either side of the shear layer. The purpose was to evaluate the effect of swirl on compressible mixing rates. Previously analytical and experimental results seem to indicate that swirling flow may significantly modify the shear layer, in some cases resulting in enhanced mixing. Previous studies of the effect of swirl on compressible mixing were incomplete since the amount of swirl in the flowfield was not quantified. This study was undertaken to conclusively determine the effect of swirl on supersonic mixing, including the quantification of the swirl. Preliminary results indicate that the swirl modestly enhances the mixing rates. Settles, Gary S. Unspecified Center...
Book Synopsis Papers Presented at the AIAA/ASME/SAE/ASEE 25th Joint Propulsion Conference by :
Download or read book Papers Presented at the AIAA/ASME/SAE/ASEE 25th Joint Propulsion Conference written by and published by . This book was released on 1989 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis A Study on the Turbulence Characteristics and Mixing Performance of Streamwise Vortex Interactions in Supersonic Flow by : Cody R. Ground
Download or read book A Study on the Turbulence Characteristics and Mixing Performance of Streamwise Vortex Interactions in Supersonic Flow written by Cody R. Ground and published by . This book was released on 2019 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: The scramjet engine offers the unique capability to enable sustained air breathing flight at hypersonic speeds. However, in order to reach its full application potential, further technological maturation of several system level components is necessary. One such component is the fuel injection system. The flow conditions characteristic of the scramjet combustor are such that the rate-limiting step in the fuel injection/mixing/combustion process is the mixing of the fuel and air. For this reason, the fuel injection system must be designed with the goal of enhancing the rate of fuel/air mixing. One method that has shown potential to enhance fuel/air mixing in supersonic flows is the introduction of streamwise vorticity into the mixing field, yet there are many fundamental aspects of this concept that remain relatively uninvestigated. One such aspect is the capability to use specific streamwise vortex interaction modes to synergistically increase mixing in the flow. However, in order to target specific vortex interactions which act to enhance mixing in the design stage of a fuel injection system a better foundational knowledge of streamwise vortex interactions in supersonic flows must be obtained. To this end, this dissertation presents a fundamental experimental investigation into two elemental modes of vortex interaction, the merging and non-merging of a pair of co-rotating streamwise vortices. The experimental investigations were all conducted at the University of Texas at Arlington Aerodynamics Research Center in the blow-down Supersonic Wind Tunnel Facility which delivered a Mach 2.5 free stream flow for all of the experiments detailed herein. To create the targeted vortex interaction modes specific configurations of vortex generating ramps were affixed to the trailing edge of a strut injector. The experiments detailed in this dissertation accomplish two tasks in the continuation of the group's previous research on the merging and non-merging modes of streamwise vortex interaction. The first task that will be presented is the analysis of the fluctuating velocity flow fields of the two studied vortex interactions with the proper orthogonal decomposition (POD) technique. This analysis is approached in order to quantify the organization and relative turbulent kinetic energy content of the various scales of turbulent coherent structures of the flow. The results of the POD analysis revealed that the vortex merging process reorients and redistributes the turbulent kinetic energy content towards the larger coherent structures captured in the low-order eigenmodes of the POD. The second task presented in this dissertation is the non-intrusive laser-based quantification of the mixing performance of the two vortex interactions using the filtered Rayleigh scattering (FRS) technique. Applying the FRS technique to retrieve mixture composition measurements in highly complex flows such as the flows studied here is a nontrivial task. For this reason, experiments were initially performed in a canonical two-dimensional planar shear layer to compare the relative accuracy of filtered Rayleigh scattering measurements with intrusive gas-sampling based mixture composition measurements. With this comparison yielding good levels of agreement between the two techniques, the FRS technique was able to be confidently applied in the vortical flows of primary interest. The main conclusion obtained from the FRS experiments was the finding that the non-merging vortex interaction more rapidly mixes the fuel and air due to its increased rate of entrainment with respect to the merging vortex interaction. Taken together, the results of the two analyses presented in this dissertation highlight the necessity of considering streamwise vortex interactions in the design stage of scramjet fuel injection systems since all differences in the flowfields of the two studied cases arise solely due to the different vortex interaction modes generated. Most importantly, this work has laid the foundation for future fundamental vortex dynamics studies which seek to optimize these (and other) modes of interaction by using the analysis and measurement techniques described herein.
Book Synopsis Air Breathing Engines and Aerospace Propulsion by : B. N. Raghunandan
Download or read book Air Breathing Engines and Aerospace Propulsion written by B. N. Raghunandan and published by Allied Publishers. This book was released on 2004 with total page 752 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contributed papers presented at the 7th National Conference on Air Breathing Engines and Aerospace Propulsion, hosted at I.I.T., Kanpur.
Book Synopsis Vortex Dynamics Studies in Supersonic Flow by : Fabrizio Vergine
Download or read book Vortex Dynamics Studies in Supersonic Flow written by Fabrizio Vergine and published by . This book was released on 2014 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt: Despite the recognized importance of streamwise vortices in the enhancement of fuel/air mixing processes in scramjet combustors, the effects of their interactions and dynamics on mixing and associated total pressure losses are still relatively unexplored. This work presents the first systematic effort to find answers to fundamental questions such as: can selected vortex interactions be identified and effectively used in an injection system for scramjets? Is the increase of streamwise vorticity content, regardless of its spatial distribution in the flow, always beneficial for entrainment and molecular mixing? Is it possible to apply vortex dynamics concepts in reacting flows? For this reason the dissertation covers the study of selected vortex interaction scenarios both in cold and high enthalpy reacting flows. Specifically, the experimental results and the analysis of the flowfields resulting from two selected supersonic vortex interaction modes in a Mach 2.5 cold flow are presented. Additionally, the experiment design based on vortex dynamics concepts and the reacting plume survey of two pylon injectors in a Mach 2.4 high enthalpy flow are shown. The cold flow experiments were conducted in the supersonic wind tunnel of the Aerodynamics Research Center at the University of Texas at Arlington. A strut injector equipped with specified ramp configurations was designed and used to produce the flowfields of interest. The reacting flow experiments were conducted in the Expansion Tube Facility located in the High Temperature Gasdynamics Laboratory of Stanford University. A detailed description of the supersonic wind tunnel, the instrumentation, the strut injector and the supersonic wake flow downstream is shown as part of the characterization of the facility. As stereoscopic particle image velocimetry was the principal flow measurement technique used in this work to probe the streamwise vortices shed from ramps mounted on the strut, this dissertation provides a deep overview of the challenges and the application of the aforementioned technique to the survey of vortical flows. Moreover, the dissertation provides a new and comprehensive analysis of the flow physics associated with these complex supersonic vortical interactions. The mean and fluctuating velocity flowfields of two selected vortex dynamics scenarios, chosen based on the outcomes of the simulations of an inviscid reduced order model developed in the research group, are presented. The same streamwise vortices (strength, size and Reynolds number) were used experimentally to investigate both a case in which the resulting dynamics evolve in a vortex merging scenario and a case in which the merging process is voluntarily avoided in order to focus the analysis on the fundamental differences associated with the amalgamation processes alone. The results from the mean flow highlight major differences between the two cases and corroborate the use of an inviscid model for the prediction of the main flow physics in the times scales considered. The analysis is also extended to turbulence quantities and concepts borrowed from incompressible turbulence theory (i.e., fluctuating Mach numbers “ 1) appear to explain interesting features of the fluctuating flowfields. Once the interactions among the vortical structures in cold flow were assessed, these vortex dynamics concepts were probed in a reacting environment. The dissertation describes the design phase of two pylon injectors based on the prediction capabilities of the aforementioned model. Then, the results of a set of combustion experiments conducted utilizing hydrogen fuel injected into a Mach 2.4, high-enthalpy (2.8 MJ/kg) air flow are discussed. The results show that, for the heat release levels considered in this study, the morphology of the plume and its evolution are remarkably close to the results produced by the model, enabling an interpretation based on vortex dynamics considerations. The persistence of the streamwise vortical structures created by the selected ramp configurations is shown together with the effectiveness of the coherent structures in successfully anchoring the flame very close to the injection point. The work shows the possibility of a new approach in the design of injection strategies (not limited to injection devices) suitable for adoption in scramjet combustors based on the ability to predict, with basic vortex dynamics concepts and a highly reduced computational cost, the main features of flows of technological interest.
Book Synopsis Streamwise Vorticity Generation and Mixing Enhancement in Free Jets by Delta-tabs by : K. B. M. Q. Zaman
Download or read book Streamwise Vorticity Generation and Mixing Enhancement in Free Jets by Delta-tabs written by K. B. M. Q. Zaman and published by . This book was released on 1993 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Numerical Simulation of Mixing Enhancement in a Hot Supersonic Jet by : C. E. Grosch
Download or read book Numerical Simulation of Mixing Enhancement in a Hot Supersonic Jet written by C. E. Grosch and published by . This book was released on 1996 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis 31st Aerospace Sciences Meeting and Exhibit: 93-0740 - 93-0779 by :
Download or read book 31st Aerospace Sciences Meeting and Exhibit: 93-0740 - 93-0779 written by and published by . This book was released on 1993 with total page 574 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis AIAA/SAE/ASME/ASEE 27th Joint Propulsion Conference: 91-2255 - 91-2319 by :
Download or read book AIAA/SAE/ASME/ASEE 27th Joint Propulsion Conference: 91-2255 - 91-2319 written by and published by . This book was released on 1991 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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:
Book Synopsis 32nd AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit by :
Download or read book 32nd AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit written by and published by . This book was released on 1996 with total page 524 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 92-3535 - 92-3564 written by and published by . This book was released on 1992 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Scientific and Technical Aerospace Reports by :
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Experiments on the Enhancement of Compressible Mixing Via Streamwise Vorticity by : J. W. Naughton
Download or read book Experiments on the Enhancement of Compressible Mixing Via Streamwise Vorticity written by J. W. Naughton and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Applied Gas Dynamics by : Ethirajan Rathakrishnan
Download or read book Applied Gas Dynamics written by Ethirajan Rathakrishnan and published by John Wiley & Sons. This book was released on 2019-02-25 with total page 656 pages. Available in PDF, EPUB and Kindle. Book excerpt: A revised edition to applied gas dynamics with exclusive coverage on jets and additional sets of problems and examples The revised and updated second edition of Applied Gas Dynamics offers an authoritative guide to the science of gas dynamics. Written by a noted expert on the topic, the text contains a comprehensive review of the topic; from a definition of the subject, to the three essential processes of this science: the isentropic process, shock and expansion process, and Fanno and Rayleigh flows. In this revised edition, there are additional worked examples that highlight many concepts, including moving shocks, and a section on critical Mach number is included that helps to illuminate the concept. The second edition also contains new exercise problems with the answers added. In addition, the information on ram jets is expanded with helpful worked examples. It explores the entire spectrum of the ram jet theory and includes a set of exercise problems to aid in the understanding of the theory presented. This important text: Includes a wealth of new solved examples that describe the features involved in the design of gas dynamic devices Contains a chapter on jets; this is the first textbook material available on high-speed jets Offers comprehensive and simultaneous coverage of both the theory and application Includes additional information designed to help with an understanding of the material covered Written for graduate students and advanced undergraduates in aerospace engineering and mechanical engineering, Applied Gas Dynamics, Second Edition expands on the original edition to include not only the basic information on the science of gas dynamics but also contains information on high-speed jets.
