forced mixer lobes in ejector designs nasa technical

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Forced mixer lobes in ejector designs - NASA Technical ...

Forced mixer lobes in ejector designs Forced mixer lobes in augmentor primary ejectors obtain a 100-percent increase in pumping over conventional design, together with nearly complete mixing in very short mixing ducts, through the generation of large scale axial vorticity in the mixing duct. The vorticity causes rapid mixing of the primary and secondary flows with low losses; since mixing ...

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Forced mixer lobes in ejector designs - NASA Technical ...

NTRS - NASA Technical Reports Server. ... Forced mixer lobes in ejector designs. Document ID. 19880058995 . Document Type. Reprint (Version printed in journal) Authors. Presz, Walter M., Jr. (United Technologies Research Center East Hartford, CT; Western New

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Forced mixer lobes in ejector designs - NASA/ADS

Jun 01, 1986  Forced mixer lobes in augmentor primary ejectors obtain a 100-percent increase in pumping over conventional design, together with nearly complete mixing in very short mixing ducts, through the generation of large scale axial vorticity in the mixing duct. The vorticity causes rapid mixing of the primary and secondary flows with low losses; since mixing length is minimized, wall friction losses ...

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Forced mixer lobes in ejector designs - NASA/ADS

Forced mixer lobes in ejector designs Presz, Walter M., Jr.; ... The ADS is operated by the Smithsonian Astrophysical Observatory under NASA Cooperative Agreement NNX16AC86A. Resources About ADS ADS Help What's New [email protected] ...

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Turbofan Forced Mixer Lobe Flow Modeling - NASA

Scientific and Technical Information Division 1988. FOREWORD ... The design of these forced mixer lobes has been ... conducted at Western New England College and UTRC under NASA sponsorship has shown mixer lobes can dramatically improve the performance of ejectors such as.

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Short efficient ejector systems - NASA Technical Reports ...

A research program was conducted to improve the performance of low pressure ratio ejector systems. The results show that short, efficient ejectors operating at nearly ideal performance are possible through the use of forced mixer lobes. Forced mixer lobes generate large scale axial vorticity which results in rapid mixing and improved diffuser performance.

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Lobed Mixer Optimization for Advanced Ejector ... - NASA

Apr 01, 1996  Lobed Mixer Optimization for Advanced Ejector Geometries The overall objectives are: 1) to pursue analytical, computational, and experimental studies that enhance basic understanding of forced mixing phenomena relevant to supersonic jet noise reduction, and 2) to integrate this enhanced understanding (analytical, computational, and empirical) into a design-oriented model of a mixer-ejector ...

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Forced mixer lobes in ejector designs Joint Propulsion ...

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Forced mixer lobes in ejector designs - CORE

Forced mixer lobes in ejector designs . ... Forced mixer lobes in augmentor primary ejectors obtain a 100-percent increase in pumping over conventional design, together with nearly complete mixing in very short mixing ducts, through the generation of large scale axial vorticity in the mixing duct. ...

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A Multidisciplinary Approach to Mixer-Ejector ... - NASA

The design of an engine for a civil supersonic aircraft presents a difficult multidisciplinary problem to propulsion system engineers. There are numerous competing requirements for the engine, such as to be efficient during cruise while yet quiet enough at takeoff to meet airport noise regulations. The use of mixer-ejector nozzles presents one possible solution to this challenge.

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Forced mixer lobes in ejector designs - CORE

Forced mixer lobes in ejector designs By Jr. Walter M. Presz, Bruce L. Morin and Robert G. Gousy Topics: FLUID MECHANICS AND HEAT TRANSFER

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US5884472A - Alternating lobed mixer/ejector concept ...

A mixer/ejector suppressor is disclosed for reducing the noise level created by the exhaust flows in gas turbines. In the preferred embodiment, the suppressor comprises a mixing ring of alternating lobes attached to the engine's tailpipe; an ejector shroud mounted onto the mixing ring; and a plurality of arcuate gaps, between the mixing ring and ejector shroud, that permit ambient air to be ...

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Lobed Mixer Optimization for Advanced Ejector Geometries ...

Abstract. The overall objectives are: 1) to pursue analytical, computational, and experimental studies that enhance basic understanding of forced mixing phenomena relevant to supersonic jet noise reduction, and 2) to integrate this enhanced understanding (analytical, computational, and empirical) into a design-oriented model of a mixer-ejector noise suppression system.

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Full Navier-Stokes analysis of a two-dimensional mixer ...

NASA Technical Memorandum ... "Forced Mixer Lobes in Ejector Designs ... One example of the type of nozzle flow analysis being conducted at the NASA Lewis Research Center is the flow in a ...

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Computational studies of lobed forced mixer flows ...

Full Navier-Stokes Analyses have been conducted for the flows behind the trailing edge of a lobed forced mixer. The governing equations are derived from the time-dependent compressible Navier-Stokes equations and discretized in the finite-difference form. A simple two-layer eddy viscosity model has also been used to account for the turbulence. Computed results are compared with some of the ...

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Numerical research on the mixing mechanism of lobed mixer ...

Feb 16, 2015  A detailed numerical simulation is presented to investigate the effects of inlet swirl and its radial distribution on the mixing mechanisms of a turbofan mixer with 12 lobes, by using the commercial ANSYS CFX solver and k–ω SST model.

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Micro-Gas Turbine Engine Ejector-Mixer Design and Testing

result serves as a base of knowledge useful to the design of a micro-gas turbine engine ejector-mixer. 4 Technical Background 4.1 Ejector-Mixer Theory As the name suggests, an ejector-mixer is composed of two parts: the ejector, and the mixer. The ejector is the shroud in which the engine exhaust primary flow and the ambient conditioned

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(PDF) Numerical Simulations of Sound radiated from ...

May 27, 2013  their continuing technical support. ... "Studies of Mixing in Ducted Fan Jet Engines," NASA Report TT F ... W. M., Gousy, R., and Morin, B., "Forced Mixer Lobes in Ejector Design," Journal of ...

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Measurements of velocities in the near field of a lobed ...

Measurements of velocities in the near field of a lobed forced mixer trailing edge - Volume 101 Issue 1003

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Some flow characteristics of lobed forced mixers at higher ...

NASA CR4147. Eckerle WA; Sheibani H; Awad J (1992) Experimental Measurement of the vortex development downstream of a lobed forced mixer. ASME J. Eng. Gas Turbines Power, Vol. 114: 63. Google Scholar Malecki R; Mityas S; Lord W (1990) Navier-Stokes analysis of an ejector and mixer ejector operating at pressure ratio in the range 2–4. AIAA ...

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Equivalence ratio and constriction effects on RBCC thrust ...

Jun 01, 2011  For example, mixing can be improved by inducing large scale axial vortices inside an ejector using either a hypermixing nozzle , , or forced mixer lobes , . Another method is to use a dual thruster arrangement which was shown to significantly improve mixing

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NASA Network Resource and Training Site : Free Texts ...

NASA Technical Reports Server (NTRS) 19960000325: Experimental investigation of wing installation effects on a two-dimensional mixer/ejector nozzle for supersonic transport aircraft Jul 1, 1992 07/92

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Influence of pressure driven secondary flows on ... - NASA/ADS

A finite difference procedure was developed to analyze the three dimensional subsonic turbulent flows in turbofan forced mixer nozzles. The method is based on a decomposition of the velocity field into primary and secondary flow components which are determined by solution of the equations governing primary momentum, secondary vorticity, thermal energy, and continuity.

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Kelvin - Helmholtz and Streamwise Vortices in the Near ...

Apr 01, 2006  Abstract. In the present experimental investigation, the characteristics of two types of vortices, namely the normal Kelvin-Helmholtz (K-H) and streamwise vortices, generated in the near wake of a lobed forced mixer were examined and evaluated at two velocity ratios (r = U 1:U 2 = 1:1 and 0.4:1). The lobed forced mixer has only one lobe and was designed to eliminate any possible interactions ...

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Forced mixer lobes in ejector designs - CORE

Forced mixer lobes in ejector designs By Jr. Walter M. Presz, Bruce L. Morin and Robert G. Gousy Topics: FLUID MECHANICS AND HEAT TRANSFER

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Design of wind turbines with shroud and lobed ejectors for ...

Sep 01, 2015  Compared to a conventional lobe forced mixer, the newly designed lobed ejector had the following characteristics: 1. The high-pressure mainstream ducted from the outside atmosphere pumped the low-pressure and low-speed secondary stream out of the turbine cascade to increase the pressure difference between the inlet and outlet of a turbine.

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US5761900A - Two-stage mixer ejector suppressor - Google ...

A two-stage mixer ejector concept ("TSMEC") is disclosed for suppressing the noise emanated by jet aircraft. This TSMEC was designed to help older engines meet the stringent new federal noise regulations, known as "Stage III". In an illustrated embodiment, the TSMEC comprises: a lobed engine nozzle attached to the rear of a turbofan engine; a short shroud that straddles the exit end of the ...

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(PDF) Numerical Simulations of Sound radiated from ...

May 27, 2013  their continuing technical support. ... "Studies of Mixing in Ducted Fan Jet Engines," NASA Report TT F ... W. M., Gousy, R., and Morin, B., "Forced Mixer Lobes in Ejector Design," Journal of ...

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Numerical research on the mixing mechanism of lobed mixer ...

Feb 16, 2015  A detailed numerical simulation is presented to investigate the effects of inlet swirl and its radial distribution on the mixing mechanisms of a turbofan mixer with 12 lobes, by using the commercial ANSYS CFX solver and k–ω SST model.

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Experimental studies on supersonic mixer-ejector using ...

Paterson RW (1984) Turbofan mixer nozzle flow field - a benchmark experimental study. J Eng for Gas Turbines and Power 106: 692–698. Google Scholar Presz WM (Jr); Gousy R; Morin BL (1986) Forced mixer lobes in ejector designs. AIAA Paper 86-1614

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Infrared signal of the lobed mixer with external air ...

May 06, 2021  The exhaust nozzle used in the experiment is a lobed mixer with a lobe of sinusoidal shape and is designed to have a penetration of 0.2. Exhaust gas temperature and infrared signal are measured according to distance from nozzle outlet under conditions of bypass ratio of 0.5, 1.0 and 1.4.

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(PDF) Progress in helicopter infrared signature suppression

tional ejector designs. The test results also indicated ... that forced mixer lobes resulted in nearly complete . ... The technical parameters of high micro/nano sizes flake Cu powders are ...

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NASA Network Resource and Training Site : Free Texts ...

NASA Technical Reports Server (NTRS) 19960000325: Experimental investigation of wing installation effects on a two-dimensional mixer/ejector nozzle for supersonic transport aircraft Jul 1, 1992 07/92

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Characteristics of helicopter engine exhaust through ...

Forced mixer lobes in ejector designs. J Propul Power 1988; 4: ... (NASA), 1979. Google Scholar. 28. Mineck RE and Gorton SA. Steady and periodic pressure measurements on a generic helicopter fuselage model in the presence of a rotor. Report no. NASA TM-2000-210286. Washington, DC: National Aeronautics and Space Administration (NASA), 2000.

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lobed mixer nozzle: Topics by Science.gov

Development of a Liner Design Methodology and Relevant Results of Acoustic Suppression in the Farfield for Mixer-Ejector Nozzles. NASA Technical Reports Server (NTRS) Salikuddin, M. 2006-01-01. We have developed a process to predict noise field interior to the ejector and in the farfield for any liner design for a

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Short efficient ejector systems - CORE

Forced mixer lobes generate large scale axial vorticity which results in rapid mixing and improved diffuser performance. Ejector testing was conducted using both an ejector wind tunnel. Numerous mixer lobe variations were tested to develop lobe design guidelines. The improved performance of mixer-ejectors is presented over a range of operating ...

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Simplified turbulence modeling for forced vortical mixers ...

May 01, 2001  Further, ejector–mixer nozzle systems provide an important signature (acoustic and thermal) treatment technology for high-speed civil transport concepts, as well as, for civilian and military, turbofan propulsion systems. A key element in the overall design is an evaluation of the turbulent mixing between streams . At the preliminary design ...

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Defense Technical Information Center

SS F 'Truncated Perfect Nozzles in Optimum Nozzle Design." ARS Journal, May 1961. 18 SPSF A T Ahren, B., "Note on the Cylindrical Ejector Supersonic Propelling Nozzle", Journal of the Royal Aeronautical Society, Volume 67, October 1963, pp. 670-671. 19 SPSF W AE Alken, T. N., "Advanced-Augmentor Wing Research", NASA SP-320, SS T Oct. 1972.

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