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Follow On Low Noise Fan Aerodynamic Study
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Author :National Aeronautics and Space Administration (NASA) Publisher :Createspace Independent Publishing Platform ISBN 13 :9781721081462 Total Pages :148 pages Book Rating :4.0/5 (814 download)
Book Synopsis Follow-On Low Noise Fan Aerodynamic Study by : National Aeronautics and Space Administration (NASA)
Download or read book Follow-On Low Noise Fan Aerodynamic Study written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-12 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: The focus of the project was to investigate the effects of turbulence models on the prediction of rotor wake structures. The Advanced Ducted Propfan Analysis (ADPAC) code was modified through the incorporation of the Spalart-Allmaras one-equation turbulence model. Suitable test cases were solved numerically using ADPAC employing the Spalart-Allmaras turbulence model and another prediction code for comparison. A near-wall spacing study was also completed to determine the adequate spacing of the first computational cell off the wall. Solutions were also collected using two versions of the algebraic Baldwin-Lomax turbulence model in ADPAC. The effects of the turbulence model on the rotor wake definition was examined by obtaining ADPAC solutions for the Low Noise Fan rotor-only steady-flow case using the standard algebraic Baldwin-Lomax turbulence model, a modified version of the Baldwin-Lomax turbulence model and the one-equation Spalart-Allmaras turbulence model. The results from the three different turbulence modeling techniques were compared with each other and the available experimental data. These results include overall rotor performance, spanwise exit profiles, and contours of axial velocity taken along constant axial locations and along blade-to-blade surfaces. Wake characterizations were also performed on the experimental and ADPAC predicted results including the definition of a wake correlation function. Correlations were evaluated for wake width and wake depth. Similarity profiles of the wake shape were also compared between all numerical solutions and experimental data. Heidegger, Nathan J. and Hall, Edward J. and Delaney, Robert A. Glenn Research Center NAS3-27394; RTOP 538-03-11
Book Synopsis Follow-on Low Noise Fan Aerodynamic Study by :
Download or read book Follow-on Low Noise Fan Aerodynamic Study written by and published by . This book was released on 1999 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Design of a Low Speed Fan Stage for Noise Suppression by :
Download or read book Design of a Low Speed Fan Stage for Noise Suppression written by and published by . This book was released on 1999 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Monthly Catalog of United States Government Publications by :
Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on 2000 with total page 658 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author :National Aeronautics and Space Administration (NASA) Publisher :Createspace Independent Publishing Platform ISBN 13 :9781722159283 Total Pages :70 pages Book Rating :4.1/5 (592 download)
Book Synopsis Advanced Low-Noise Research Fan Stage Design by : National Aeronautics and Space Administration (NASA)
Download or read book Advanced Low-Noise Research Fan Stage Design written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-02 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes the design of the Advanced Low-Noise Research Fan stage. The fan is a variable pitch design, which is designed at the cruise pitch condition. Relative to the cruise setting, the blade is closed at takeoff and opened for reverse thrust operation. The fan stage is a split flow design with fan exit guide vanes (FEGVs) and core stators. The fan stage design is combined with a nacelle and engine core duct to form a powered fan/nacelle subscale model. This model is intended for use in combined aerodynamic, acoustic, and structural testing in a wind tunnel. The fan has an outer diameter of 22 in. and a hub-to-tip of 0.426 in., which allows the use of existing NASA fan and cowl force balance and rig drive systems. The design parameters were selected to permit valid acoustic and aerodynamic comparisons with the Pratt & Whitney (P&W) 17- and 22-in. rigs previously tested under NASA contract. The fan stage design is described in detail. The results of the design axisymmetric and Navier-Stokes aerodynamic analysis are presented at the critical design conditions. The structural analysis of the fan rotor and attachment is included. The blade and attachment are predicted to have adequate low-cycle fatigue life and an acceptable operating range without resonant stress or flutter. The stage was acoustically designed with airfoil counts in the FEGV and core stator to minimize noise. A fan/FEGV tone analysis developed separately under NASA contract was used to determine the optimum airfoil counts. The fan stage was matched to the existing nacelle, designed under the previous P&W low-noise contract, to form a fan/nacelle model for wind tunnel testing. It is an axisymmetric nacelle for convenience in testing and analysis. Previous testing confirmed that the nacelle performed as required at various aircraft operating conditions. Neubert, Robert and Bock, Larry and Malmborg, Eric and Owen-Peer, William Glenn Research Center...
Author :National Aeronautics and Space Administration (NASA) Publisher :Createspace Independent Publishing Platform ISBN 13 :9781726187411 Total Pages :50 pages Book Rating :4.1/5 (874 download)
Book Synopsis Aerodynamic Performance Measurements for a Forward Swept Low Noise Fan by : National Aeronautics and Space Administration (NASA)
Download or read book Aerodynamic Performance Measurements for a Forward Swept Low Noise Fan written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-29 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: One source of noise in high tip speed turbofan engines, caused by shocks, is called multiple pure tone noise (MPT's). A new fan, called the Quiet High Speed Fan (QHSF), showed reduced noise over the part speed operating range, which includes MPT's. The QHSF showed improved performance in most respects relative to a baseline fan; however, a partspeed instability discovered during testing reduced the operating range below acceptable limits. The measured QHSF adiabatic efficiency on the fixed nozzle acoustic operating line was 85.1 percent and the baseline fan 82.9 percent, a 2.2 percent improvement. The operating line pressure rise at design point rotational speed and mass flow was 1.764 and 1.755 for the QHSF and baseline fan, respectively. Weight flow at design point speed was 98.28 lbm/sec for the QHSF and 97.97 lbm/sec for the baseline fan. The operability margin for the QHSF approached 0 percent at the 75 percent speed operating condition. The baseline fan maintained sufficient margin throughout the operating range as expected. Based on the stage aerodynamic measurements, this concept shows promise for improved performance over current technology if the operability limitations can be solved.Fite, E. BrianGlenn Research CenterAERODYNAMIC CHARACTERISTICS; TURBOFAN ENGINES; FAN BLADES; NOISE GENERATORS; AERODYNAMIC NOISE; ACOUSTIC DELAY LINES; MASS FLOW; VORTICES; TIP SPEED...
Book Synopsis Advanced Low-Noise Research Fan Stage Design by :
Download or read book Advanced Low-Noise Research Fan Stage Design written by and published by . This book was released on 1997 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Low Noise Research Fan Stage Design by :
Download or read book Low Noise Research Fan Stage Design written by and published by . This book was released on 1995 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Two Stage Low Noise Advanced Technology Fan. 1: Aerodynamic, Structural, and Acoustic Design by :
Download or read book Two Stage Low Noise Advanced Technology Fan. 1: Aerodynamic, Structural, and Acoustic Design written by and published by . This book was released on 1974 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Aerodynamic Research and the Low-noise Aircraft by : I. Chichester-Miles
Download or read book Aerodynamic Research and the Low-noise Aircraft written by I. Chichester-Miles and published by . This book was released on 1977 with total page 12 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 1972 with total page 1056 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book STAR written by and published by . This book was released on 1973 with total page 892 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Aerodynamic Experiments on a Ducted Fan in Hover and Edgewise Flight by : Leighton Montgomery Myers
Download or read book Aerodynamic Experiments on a Ducted Fan in Hover and Edgewise Flight written by Leighton Montgomery Myers and published by . This book was released on 2009 with total page 275 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ducted fans and ducted rotors have been integrated into a wide range of aerospace vehicles, including manned and unmanned systems. Ducted fans offer many potential advantages, the most important of which is an ability to operate safely in confined spaces. There is also the potential for lower environmental noise and increased safety in shipboard operations (due to the shrouded blades). However, ducted lift fans in edgewise forward flight are extremely complicated devices and are not well understood. Future development of air vehicles that use ducted fans for lift (and some portion of forward propulsion) is currently handicapped by some fundamental aerodynamic issues. These issues influence the thrust performance, the unsteadiness leading to vehicle instabilities and control, and aerodynamically generated noise. Less than optimum performance in any of these areas can result in the vehicle using the ducted fan remaining a research idea instead of one in active service. The Penn State Department of Aerospace Engineering initiated an experimental program two years ago to study the aerodynamics of ducted lift fans. The focus of this program from its initiation was to study a single lift fan subject to an edgewise mean flow. Of particular concern was the transitional flow regime from hover to a relatively high forward speed in which a major portion of the vehicle lift is produced by the aerodynamic forces on the body. We refer to this as ducted fan edgewise flow. There are four obvious consequences of operating a ducted lift fan in edgewise (forward) flow. First, separations off the leading portion of the duct can reduce the inflow and thus the thrust of the fan. Second, the separated flow will lead to unsteadiness which will undoubtedly decrease the control authority of the vehicle. Thirdly, the outer surface of the fan shroud is likely to be fairly blunt. This body shape, together with the strong momentum drag of the lift fan outflow, produce excessive drag forces that increase the requirements of the propulsion devices. Finally, increased turbulence of the inflow will also result in increased production of aerodynamic noise. The goals of this project are to conduct detailed experiments on several configurations of ducted lift fans in hover and edgewise flow. Single ducted lift fan configurations involve different shrouded duct shapes and rotor shapes. Rotors are tested with a range of solidities and tip clearances. Including inlet duct vents over the forward portion of the duct shroud, has the potential of reducing the problem of separated flow over the forward portion of the duct inlet, and potentially reducing the drag of the vehicle in forward flight.
Book Synopsis Federal Aircraft Noise Abatement Plan by :
Download or read book Federal Aircraft Noise Abatement Plan written by and published by . This book was released on 1969 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fossil Energy Update written by and published by . This book was released on 1978 with total page 944 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Technical Paper written by and published by . This book was released on 1990 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author :United States. Congress. House. Committee on Science and Astronautics Publisher : ISBN 13 : Total Pages :1448 pages Book Rating :4.3/5 (91 download)
Book Synopsis Hearings by : United States. Congress. House. Committee on Science and Astronautics
Download or read book Hearings written by United States. Congress. House. Committee on Science and Astronautics and published by . This book was released on 1972 with total page 1448 pages. Available in PDF, EPUB and Kindle. Book excerpt:
