Download or read book Evaluation of Boattail Geometry and Exhaust Plume Temperature Effects on Nozzle Afterbody Drag at Transonic Mach Numbers written by L. L. Galigher and published by . This book was released on 1976 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental program was conducted to investigate the interaction effects which occur between the nozzle exhaust flow and the external flow field associated with isolated nozzle afterbody configurations at transonic Mach numbers. Pressure data were obtained from three afterbody geometries with boattail angles of 10, 15, and 25 deg at Mach numbers from 0.6 to 1.5 at zero angles of attack and sideslip. Cold (High-pressure air) and hot (Air/ethylene combustion) jet test techniques were used to simulate and duplicate, respectively, the nozzle exhaust flow for a sonic jet installation. Nozzle exhaust temperature was varied from 540 to approximately 2,900 R. The most significant results pertain to those effects on boattail pressure drag caused by exhaust plume temperature and flow asymmetry (Model support strut induced). The differences obtained in boattail pressure drag between the cold jet simulation and hot jet duplication results were significant at nozzle pressure ratios representative for turbofan and turbojet engines at subsonic Mach numbers. Adjusting the cold jet nozzle pressure ratio to correct for changes in the exhaust plume specific heat ratio with temperature did not account for the differences observed. Flow asymmetry effects were Mach number and nozzle pressure ratio dependent and increased in severity as the boattail angle was increased.
Download or read book Evaluation of Boattail Geometry and Exhaust Plume Temperature Effects on Nozzle Afterbody Drag at Transonic Mach Numbers written by L. L. Galigher and published by . This book was released on 1976 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental program was conducted to investigate the interaction effects which occur between the nozzle exhaust flow and the external flow field associated with isolated nozzle afterbody configurations at transonic Mach numbers. Pressure data were obtained from three afterbody geometries with boattail angles of 10, 15, and 25 deg at Mach numbers from 0.6 to 1.5 at zero angles of attack and sideslip. Cold (High-pressure air) and hot (Air/ethylene combustion) jet test techniques were used to simulate and duplicate, respectively, the nozzle exhaust flow for a sonic jet installation. Nozzle exhaust temperature was varied from 540 to approximately 2,900 R. The most significant results pertain to those effects on boattail pressure drag caused by exhaust plume temperature and flow asymmetry (Model support strut induced). The differences obtained in boattail pressure drag between the cold jet simulation and hot jet duplication results were significant at nozzle pressure ratios representative for turbofan and turbojet engines at subsonic Mach numbers. Adjusting the cold jet nozzle pressure ratio to correct for changes in the exhaust plume specific heat ratio with temperature did not account for the differences observed. Flow asymmetry effects were Mach number and nozzle pressure ratio dependent and increased in severity as the boattail angle was increased.
Download or read book Exhaust Plume Temperature Effects on Nozzle Afterbody Performance Over the Transonic Mach Number Range written by C. E. Robinson and published by . This book was released on 1974 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results of an experimental and analytical research investigation on nozzle/afterbody drag are presented. Experimental afterbody (and boattail) drag coefficients and pressure distributions are discussed for an isolated, strut-mounted nozzle/afterbody model for the Mach number range from 0.6 to 1.5. Some data are also given for free-stream unit Reynolds numbers from one million to approximately four million per foot. The experimental data were obtained for the basic model with an air-cooled and a water-cooled Ethylene/air combustor to provide hot-jet duplication as well as cold-jet simulation. The temperature of the nozzle exhaust gas was varied from 530R (burner-off) to approximately 2500R for several nozzle pressure ratios from jet-off to those corresponding to a moderately under-expanded exhaust plum. The initial series of experiments was conducted with the air-cooled combustors, and the effect of jet temperature on afterbody drag was somewhat masked by the effects of the secondary airflow from the cooling air. The general trend, however, shows a decreasing afterbody drag with increasing exhaust gas temperature and with decreasing secondary airflow at a fixed nozzle pressure ratio. (Modified author abstract).
Download or read book NASA Technical Memorandum written by and published by . This book was released on 1980 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Reynolds Number and Tunnel Wall Porosity Effects on Nozzle Afterbody Drag at Transonic Mach Numbers written by C. E. Robinson and published by . This book was released on 1976 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental investigation was conducted to study the effects of Reynolds number variation on isolated nozzle afterbody performance. A strut-mounted cone-cylinder model with three separate afterbody configurations for Aerospace Research and Development (AGARD) was used for this investigation. This program was conducted in two phases distinguished by the model size and the wind tunnels used to obtain the experimental results. The effect of tunnel wall porosity on nozzle afterbody (NAB) performance was investigated.
Download or read book Computation of Axisymmetric Separated Nozzle afterbody Flow written by James L. Jacocks and published by . This book was released on 1980 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of a computer program for solving the compressible, axisymmetric, mass-averaged Navier-Stokes equations is described. The basic numerical algorithm is the MacCormack explicit predictor-corrector scheme. Turbulence modeling is accomplished using an algebraic, two-layer eddy viscosity model with a novel modification dependent on the streamwise gradient of vorticity. Comparisons of computed results with experimental data are presented for several nozzle-afterbody configurations with either or simulated plumes. (Author).
Download or read book An Investigation of F 16 Nozzle afterbody Forces at Transonic Mach Numbers with Emphasis on Support System Interference written by Earl A. Price (Jr.) and published by . This book was released on 1979 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive experimental program was conducted to provide nozzle-afterbody data with a minimum interference support system on a 1/9-scale F-16 model and to determine the interference induced on the afterbody-nozzle region by a sting, a wingtip, and a strut model support system. The investigation was conducted over the Mach number range from 0.6 to 1.5 and at angles of attack from 0 to 9 deg. Interference was evaluated by comparison of nozzle-afterboy axial and normal forces obtained from integrating pressure data. The results include parametric studies of the efects of various components of the wingtip support system (i.e., the support blade axial position, wingtip boom diameter, boom spacing, and boom-tip axial location). High-pressure air at ambient temperature was utilized for exhaust plume simulation. The results indicate that a sting support passing through the nozzle with the jet effects simulated by an annular jet appears to offer a minimum interference support system for the type of nozzle-afterbody test described in this report.
Download or read book A Parametric Investigation of the Annular Jet Concept for Obtaining Afterbody Drag Data at Transonic Mach Numbers written by Earl A. Price (Jr.) and published by . This book was released on 1978 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Method for Estimating Jet Entrainment Effects on Nozzle afterbody Drag written by R. C. Bauer and published by . This book was released on 1980 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: A highly simplified analysis was used to derive an expression for estimating the induced afterbody drag caused by the turbulent jet-mixing process. The approach estimates the induced velocity produced by the jet-mixing process and uses small perturbation concepts to estimate the resulting pressure change on the afterbody surface from which the induced afterbody drag coefficient is obtained. The theoretical induced afterbody drag (entrainment drag) is combined with the maximum jet plume diameter blockage condition to form a correlation method that accounts for the effect of jet area ratio, exit angle, total temperature, molecular weight and ratio of specific heats for a given external stream Mach number, Reynolds number, and afterbody geometry. For verification, the correlation method was used to predict the drag of an H2 and C2H4 jet from the measured drag of an N2 jet and to predict the drag of a hot jet from the measured drag of a cold jet for both the 15- and 25-deg AGARD afterbody configurations in the Mach number range from 0.6 to 1.5. The average accuracy of the correlation method is better than 10% for both afterbody configurations and is 40 to 50 % more accurate than a correlation method based only on the blockage parameter. A brief numerical study indicates that the major parameter which correlates the jet entrainment effect is the product of the jet gas constant and total temperature. (Author).
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1979 with total page 1074 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Analysis of Transonic Viscous inviscid Interactions on Axisymmetric Bodies with Solid Strings Or Real Plumes written by Steven F. Yaros and published by . This book was released on 1978 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Evaluation of Jet Simulation Parameters for Nozzle Afterbody Testing at Transonic Mach Numbers written by William Lee Peters and published by . This book was released on 1976 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this investigation was to evaluate various jet simulation parameters in an attempt to establish a method of matching hot jet interference with cold jet flows. Successful parameters were determined based on their ability to correlate integrated afterbody pressure drag, a measurement of aerodynamic interference, for jet flows of varying total temperature. Data used in this investigation were obtained from experiments conducted in the AEDC Propulsion Wind Tunnel (16T) with three different isolated nozzle/afterbody configurations at free-stream Mach numbers from 0.6 to 1.5. Gas temperature effects on pressure drag were acquired with a convergent nozzle utilizing an air/ethylene burner to produce gas temperatures from 540 to 3,300 R. In addition, the jet effects of varying internal nozzle geometry, specifically nozzle divergence half-angle and nozzle exit-to-throat area ratio, were investigated utilizing high-pressure air as the nozzle exhaust gas. Jet simulation parameters were evaluated for jet flows where nozzle exit-to-throat area ratio was varied from 1.0 to approximately 1.5 and where divergence half-angle was varied from 0 to 10 deg.
Download or read book Exhaust Plume Thermodynamic Effects on Nonaxisymmetric Nozzle Afterbody Performance in Transonic Flow written by C. E. Robinson and published by . This book was released on 1978 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental investigation was conducted to determine the effect of exhaust plume thermodynamic properties on a nonaxisymmetric nozzle afterbody. The model consisted of a strut-mounted cone-cylinder with an isolated nozzle afterbody. The shape of the nozzle afterbody was generally based on the early configurations of the ADEN design. An ethylene/air combustor was used to vary the thermodynamic properties by varying fuel-to-air ratio. Data were obtained at four fuel-to-air ratios representing exhaust plume temperatures of approximately 500 F (cold flow, fuel-to-air = 0), 1,200, 1,500, and 1,900 R. Pressure measurements of the nozzle afterbody surface were obtained from which drag coefficients along the rows of pressure orifices were calculated. The investigation was conducted over a range of Mach numbers from 0.6 to 1.4 at a Reynolds number per foot of 2.5 million. Generally, the nozzle afterbody drag decreased with increasing exhaust plume temperature over the entire Mach number range.
Download or read book Bibliography on Aerodynamics of Airframe engine Integration of High speed Turbine powered Aircraft Volume 1 written by and published by . This book was released on 1980 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Aeronautical Journal written by and published by . This book was released on 1994 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International Journal of Turbo Jet engines written by and published by . This book was released on 1986 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Journal of Aircraft written by and published by . This book was released on 1998 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt:
