A Preliminary Investigation of the Pressure Recovery of Several Two-dimensional Supersonic Inlets at a Mach of 2.01 PDF Download

Author: Raymond J. Comenzo
Publisher:
ISBN:
Category :
Languages : en
Pages : 28

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Author: Ione D. V. Faro
Publisher:
ISBN:
Category : Aerodynamics, Supersonic
Languages : en
Pages : 186

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The design and operation of supersonic inlets is discussed. The means by which the incoming flow may be decelerated to a subsonic velocity are enumerated and evaluated. This report covers diffusers which employ internal compression, external compression or a combination of the two. Experimentally determined values of the total pressure recovery, the capture-area ratio and the inlet drag are compared with those determined from available theories for all types of diffusers. The discussions which in general refer to axisymmetric configurations usually may be applied with equal validity to two-dimensional diffusers. However, some specific problems of the latter are treated. The effects of boundary layer are considered in some detail as are the problems of oscillating flow. (Author).

Author: T. W. Tsukahira
Publisher:
ISBN:
Category : Aerodynamics, Supersonic
Languages : en
Pages : 904

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Reported herein are the results of an investigation whose primary objective was to develop design criteria and performance tradeoffs for supersonic inlets applicable to advanced tactical aircraft. The objective was accomplished by conducting analysis and wind tunnel tests. The baseline models included a two-dimensional external compression inlet, a two-dimensional mixed compression inlet, and a half-axisymmetric external compression inlet. Alternate configurations for the external compression baseline inlets in the AEDC PWT-4T and VKF-A wind tunnels, respectively. The inlets were tested both isolated and in a non-uniform flow field, the later representing partial simulation of a vehicle flow field. Inlet steady state performance was characterized in terms of pressure recovery, pressure distortion, and turbulence levels at a simulated compressor face and immediately downstream of the inlet throat. In addition, detailed analysis and correlation of data obtained with high response dynamic instrumentation were made.

Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722970796
Category :
Languages : en
Pages : 136

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An aerodynamic and acoustic investigation was performed on two small-scale supersonic inlets to determine which inlet would be more suitable for a High Speed Civil Transport (HSCT) aircraft during approach and takeoff flight conditions. The comparison was made between an axisymmetric supersonic P inlet and a bifurcated two-dimensional supersonic inlet. The 1/14 scale model supersonic inlets were used in conjunction with a 4.1 in (10.4 cm) turbofan engine simulator. A bellmouth was utilized on each inlet to eliminate lip separation commonly associated with airplane engine inlets that are tested under static conditions. Steady state measurements of the aerodynamic flowfield and acoustic farfield were made in order to evaluate the aeroacoustic performance of the inlets. The aerodynamic results show the total pressure recovery of the two inlets to be nearly identical, 99% at the approach condition and 98% at the takeoff condition. At the approach fan speed (60% design speed), there was no appreciable difference in the acoustic performance of either inlet over the entire 0 deg to 110 deg farfield measurement sector. The inlet flow field results at the takeoff fan speed (88% design speed), show the average inlet throat Mach number for the P inlet (Mach 0.52) to be approximately 2 times that of the 2D inlet (Mach 0.26). The difference in the throat Mach number is a result of the smaller throughflow area of the P inlet. This reduced area resulted in a 'soft choking' of the P inlet which lowered the tone and overall sound pressure levels of the simulator in the forward sector by an average of 9 dB and 3 dB, respectively, when compared to the 2D inlet. Ng, Wing Glenn Research Center AEROACOUSTICS; SUPERSONIC INLETS; ENGINE INLETS; AIRCRAFT ENGINES; FLOW DISTRIBUTION; FLOW MEASUREMENT; MACH NUMBER; INLET FLOW; SUPERSONIC TRANSPORTS; CIVIL AVIATION; TAKEOFF; APPROACH; TURBOFAN ENGINES; SCALE MODELS; SIMULATORS; SOUND PRESSURE; PRESSURE RECOVERY; FAR FIELDS; ACOUSTIC PROPERTIES...

Author: Frederick K. Hube
Publisher:
ISBN:
Category : Aerodynamics, Supersonic
Languages : en
Pages : 274

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Author: Albert H. Schroeder
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 18

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Author: T. W. Tsukahira
Publisher:
ISBN:
Category : Aerodynamics, Supersonic
Languages : en
Pages : 330

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Presented herein are wind tunnel data from an investigation whose primary objective was to develop design criteria and performance tradeoffs for supersonic inlets applicable to advanced tactical aircraft. The objective was accomplished by conducting analysis and wind tunnel tests using approximately . 125 scale model air induction systems. The baseline models included a two- dimensional external compression inlet, a half-axisymmetric external compression inlet, and a two-dimensional mixed compression inlet. Alternate configurations for the external compression baseline inlets were also investigated. Tests were conducted at transonic and supersonic Mach numbers in the AEDC PWT-4T and VKF-A wind tunnels, respectively. The inlets were tested both isolated and in a well defined nonuniform flow field, the latter representing partial simulation of a vehicle flow field. Steady state performance data (i.e., pressure recovery, pressure distortion, and turbulence levels) are provided at a simulated compressor face and immediately downstream of the inlet throat for the various inlet configurations tested. Additional diagnostic data are provided in the way of surface pressures and boundary layer pressures on the inlet compression surfaces and in the subsonic diffusers.

Author: Ezgihan Baydar
Publisher:
ISBN:
Category : Inlets
Languages : en
Pages : 116

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Vortex generators (VGs) within external-compression supersonic inlets for Mach 1.6 were investigated to determine their ability to increase total pressure recovery and reduce total pressure distortion. Ramp and vane-type VGs were studied. The geometric factors of interest included height, length, spacing, angle-of-incidence, and positions upstream and downstream of the inlet terminal shock. The flow through the inlet was simulated numerically through the solution of the steady-state, Reynoldsaveraged Navier-Stokes equations on multi-block, structured grids using the WindUS flow solver. The inlet performance was characterized by the inlet total pressure recovery and the radial and circumferential total pressure distortion indices at the engine face. Previous research of downstream VGs in the low-boom supersonic inlet demonstrated improvement in radial distortion up to 24% while my work on external-compression supersonic inlets improved radial distortion up to 86%, which is significant. The design of experiments and statistical analysis methods were applied to quantify the effect of the geometric factors of VGs and search for optimal VG arrays. From the analysis, VG angle-of-incidence and VG height were the most influential factors in increasing total pressure recovery and reducing distortion. The study on the two-dimensional external-compression inlet determined which passive flow control devices, such as counter-rotating vanes or ramps, reduce high distortion levels and improve the health of the boundary layer, relative to the baseline. Downstream vanes demonstrate up to 21% improvement in boundary layer health and 86% improvement in radial distortion. Upstream vanes demonstrated up to 3% improvement in boundary layer health and 9% improvement in radial distortion. Ramps showed no improvement in boundary layer health and radial distortion. Micro-VGs were preferred for their reduced viscous drag and improvement in total pressure recovery at the AIP. Although traditional VGs energize the flow with stronger vortex structures compared to micro-VGs, the AIP is affected with overwhelming amounts of reduced and enhanced flow regions. In summary, vanes are exceptional in reducing radial distortion and improving the health of the boundary layer compared to the ramps. In the study of the STEX inlet, vane-type vortex generators were the preferred devices for boundary layer flow control. In the supersonic diffuser, co-rotating vane arrays and counter-rotating vane arrays did not show improvement. In the subsonic diffuser, co-rotating vane arrays with negative angles-of-incidence and counterrotating vane arrays were exceptional in reducing radial distortion and improving total pressure recovery. Downstream co-rotating vanes demonstrated up to 41% improvement in radial distortion whereas downstream counter-rotating vanes demonstrated up to 73% improvement. For downstream counter-rotating vanes, a polynomial trend between VG height and radial distortion indicate that increasing VG height improves inlet distortion. In summary, downstream vanes are exceptional in improving total pressure recovery compared to upstream vanes.

Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781719390408
Category :
Languages : en
Pages : 26

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A computational tool named SUPIN has been developed to design and analyze external-compression supersonic inlets for aircraft at cruise speeds from Mach 1.6 to 2.0. The inlet types available include the axisymmetric outward-turning, two-dimensional single-duct, two-dimensional bifurcated-duct, and streamline-traced Busemann inlets. The aerodynamic performance is characterized by the flow rates, total pressure recovery, and drag. The inlet flowfield is divided into parts to provide a framework for the geometry and aerodynamic modeling and the parts are defined in terms of geometric factors. The low-fidelity aerodynamic analysis and design methods are based on analytic, empirical, and numerical methods which provide for quick analysis. SUPIN provides inlet geometry in the form of coordinates and surface grids useable by grid generation methods for higher-fidelity computational fluid dynamics (CFD) analysis. SUPIN is demonstrated through a series of design studies and CFD analyses were performed to verify some of the analysis results. Slater, John W. Glenn Research Center COMPUTATIONAL FLUID DYNAMICS; SUPERSONIC INLETS; FLOW DISTRIBUTION; AERODYNAMIC CHARACTERISTICS; DRAG; FLOW VELOCITY; SUPERSONIC SPEED; DUCTS; PRESSURE RECOVERY; DESIGN ANALYSIS

Author: Widen Tabakoff
Publisher:
ISBN:
Category : Aerodynamics, Hypersonic
Languages : en
Pages : 43

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The report describes the experimental measurement of pressure recovery across a simulated combustion chamber duct of a two-dimensional hypersonic inlet with variable geometry. The model tested was a wedge type inlet which generated a single external shock wave. The program was conducted in the twenty-inch hypersonic wind tunnel. Testing was at a nominal free stream Mach number of 14 and free stream Reynolds number of 721,000 per foot. (Author).