Download or read book A Study of the Compressible Flow Through a Diffusing S Duct written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-17 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: Benchmark aerodynamic data are presented for compressible flow through a representative S-duct configuration. A numerical prediction of the S-duct flow field, obtained from a subsonic parabolized Navier-Stokes algorithm, is also shown. The experimental and numerical results are compared. Measurements of the three-dimensional velocity field, total pressures, and static pressures were obtained at five cross-sectional planes. Aerodynamic data were gathered with calibrated pneumatic probes. Surface static pressure and surface flow visualization data were also acquired. All reported tests were conducted with an inlet centerline Mach number of 0.6. The Reynolds number, based on the inlet centerline velocity and duct inlet diameter, was 2.6 x 10(exp 6). Thin inlet turbulent boundary layers existed. The collected data should be beneficial to aircraft inlet designers and the measurements are suitable for the validation of computational codes. The results show that a region of streamwise flow separation occurred within the duct. Details about the separated flow region, including mechanisms which drive this complicated flow phenomenon, are discussed. Results also indicate that the duct curvature induces strong pressure driven secondary flows. The cross flows evolve into counter-rotating vortices. These vortices convect low momentum fluid of the boundary layer toward the center of the duct, degrading both the uniformity and magnitude of the total pressure profile. Wellborn, Steven R. and Okiishi, Theodore H. and Reichert, Bruce A. Glenn Research Center COMPRESSIBLE FLOW; COMPUTATIONAL FLUID DYNAMICS; DUCTED FLOW; FLOW DISTRIBUTION; NAVIER-STOKES EQUATION; PRESSURE DISTRIBUTION; SUBSONIC FLOW; THREE DIMENSIONAL MOTION; VELOCITY DISTRIBUTION; WIND TUNNEL TESTS; BOUNDARY LAYER SEPARATION; CROSS FLOW; FLOW VISUALIZATION; INLET FLOW; REYNOLDS NUMBER; STAGNATION PRESSURE; STATIC PRESSURE; TURBULENT BOUNDARY LAYER; VORTICES...

Download or read book A Study of the Compressible Flow Through a Diffusing S duct written by Steven Robert Wellborn and published by . This book was released on 1993 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Study of the Compressible Flow Through a Diffusing S duct written by Theodore H. Okiishi and published by . This book was released on 1993 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Three Dimensional Compressible Turbulent Computations for a Diffusing S Duct written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-10-15 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of the present study was to evaluate the capability of the computational fluid dynamics computer program PARC3D to model flow in a typical diffusing subsonic S-duct, with strong secondary flows. This evaluation is needed to provide confidence in the analysis of aircraft inlets, which have similar geometries. The performance predictions include total pressure profiles, static pressures, velocity profiles, boundary layer data, and skin friction data. Flow in the S-duct is subsonic, and the boundary layers are assumed to be turbulent. The results for both H and O grid solutions, are compared with existing test data. Smith, C. F. and Bruns, J. E. and Harloff, G. J. and Debonis, J. R. Unspecified Center NAS3-25266; RTOP 533-02-30

Download or read book Numerical Simulation of Separated and Secondary Flows in Diffusing S ducts for Air Breathing Propulsion written by Colin J. Fiola and published by . This book was released on 2013 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: The focus of this thesis is on numerical simulation of incompressible and compressible flow in a diffusing S-duct inlet. S-ducts are very common components of both commercial and militaryaircraft, for example the Boeing 727 and McDonnell Douglas F-18. The F-18, being a relatively small aircraft, requires a short, highly curved S-duct with non-uniform cross-sectional area. The S-duct decelerates the flow, increasing the static pressure, in order to provide a uniform velocity and pressure distribution at the engine face. The curved nature and increasing cross sectional area creates secondary flows and boundary layer separation which causes non-uniform flow and total pressure loss at the engine face. Total pressure loss and flow non-uniformity at the engine face reduce engine performance and cause increased wear on parts such as turbine blades. Engine stall is also a concern when the flow inside the S-Duct becomes highly distorted. An ideal S-duct would efficiently decelerate flow uniformly while minimizing total pressure loss and magnitude of transverse velocity components. Due to the necessity to minimize size and maximize stealth of aircraft, including Unmanned Aerial Vehicles (UAVs) and cruise missiles, designers are challenged to use shorter and more highly curved S-Ducts. The accurate modeling of flow in S-duct is therefore a problem of great interest and significance in propulsion. In this thesis, we study the flow field in S-ducts by numerical simulations using the Reynolds-Averaged Navier-Stokes (RANS) equations in conjunction with a variety of one - and two equation turbulence models such as one-equation Spalart-Allmaras model, the two-equation k-[epsilon] and SST k-[omega] models, and the four equations Transition SST model. Two S-duct geometries are employed in this investigation - one is used in an experimental study conducted at NASA Glenn Research Center in the early 1990's, the other is a benchmark configuration proposed by AIAA Propulsion Aerodynamics Workshop to assess the accuracy and best practices of CFD solvers. The CFD flow solver ANSYS-FLUENT is employed for computing the incompressible/compressible flow inside the S-ducts. A structured mesh is generated using GAMBIT. A second-order accurate steady density-based solver is employed in a finite-volume framework. The computed results compare well with the experimental data and with the computations of other investigators. The flow field and pressure recovery are captured with good accuracy. The best practices for CFD modeling, namely the mesh density, the accuracy of the algorithm and the turbulence model, of S-duct flow field are identified.

Download or read book Computational Study of Compressible Flow in an S shaped Duct written by Varangrat Suratanakavikul and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Three Dimensional Compressible Turbulent Flow Computations for a Diffusing S duct With without Vortex Generators written by Soo-Yong Cho and published by . This book was released on 1994 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Study of Compressible Flow Through a Rectangular to semiannular Transition Duct written by and published by . This book was released on 1995 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Study of Compressible Flow Through a Rectangular to semiannular Transition Duct written by Jeffry Foster and published by . This book was released on 1995 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Study of Compressible Flow Through a Rectangular to semianular Transition Duct written by Jeffry Duane Foster and published by . This book was released on 1995 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book New Results in Numerical and Experimental Fluid Mechanics XI written by Andreas Dillmann and published by Springer. This book was released on 2017-10-29 with total page 735 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gathers contributions to the 20th biannual symposium of the German Aerospace Aerodynamics Association (STAB) and the German Society for Aeronautics and Astronautics (DGLR). The individual chapters reflect ongoing research conducted by the STAB members in the field of numerical and experimental fluid mechanics and aerodynamics, mainly for (but not limited to) aerospace applications, and cover both nationally and EC-funded projects. Special emphasis is given to collaborative research projects conducted by German scientists and engineers from universities, research-establishments and industries. By addressing a number of cutting-edge applications, together with the relevant physical and mathematics fundamentals, the book provides readers with a comprehensive overview of the current research work in the field. Though the book’s primary emphasis is on the aerospace context, it also addresses further important applications, e.g. in ground transportation and energy.

Download or read book An Experimental Investigation of the Flow in a Diffusing S duct written by S. R. Wellborn and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advances in Sustainable Aviation written by Tahir Hikmet Karakoç and published by Springer. This book was released on 2017-11-08 with total page 289 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides different engineering, management, economic solutions and methodologies regarding sustainable aviation, giving readers a great sense of how sustainable aviation works at the “systems” level. The aviation industry is one of the fastest growing in the world and can make a positive contribution to sustainability. This book presents environmental policies and their application to the aviation industry and evaluates solutions provided to address pollution. Chapters discuss novel technologies that the aviation industry can apply to reduce its environmental impact and become more energy efficient.

Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1993 with total page 528 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:

Download or read book Monthly Catalogue United States Public Documents written by and published by . This book was released on 1994 with total page 1064 pages. Available in PDF, EPUB and Kindle. Book excerpt: