Download or read book Influence of Surface Roughness on Compressor Blades at High Reynolds Number in a Two Dimensional Cascade written by G. P. Moe and published by . This book was released on 1984 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a thesis. A cascade test facility has been established which incorporates sidewall boundary layer control, permitting two-dimensional flow investigation over the center span (about 2/3 the width of the blade) of an airfoil in cascade, and an investigation has been conducted to determine the influence of roughness on the airfoil. Two representative compressor profiles, the NACA 64-A905 and 65-A506, with two inch chords and aspect ratios of one were tested at airflow inlet velocities comparable to those axial flow compressors. An Axial Velocity Density Ratio of unity was the criterion used to determine when two-dimensional flow was achieved. Test results indicate that initial small increases of roughness have a much greater effect on blade total pressure loss than do subsequent larger roughness values. A small increase in roughness produces a substantial increase in free stream turbulence with practically no effect on the wake. Further increase in roughness produces a substantial effect on the wake but little effect on the free stream turbulence. Surface roughness is shown to have a much greater influence on blade wake turbulence intensity for the higher camber airfoils tested than for lower camber airfoils. Keywords include: Cascade Testing, Two-Dimensional Flow Compressor Blades, Roughness Effects, Boundary Layer.
Download or read book Influence of Surface Roughness on Compressor Blades at High Reynolds Number in a Two dimensional Cascade written by Gary P. Moe (CAPT, USAF.) and published by . This book was released on 1984 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Surface Roughness on Pressure Distribution and Boundary Layer Over Compressor Blades at High Reynolds Number in a Two Dimensional Cascade written by Larry D. Williams and published by . This book was released on 1985 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this evaluation of the effects of surface roughness on the pressure distribution and boundary layer over compressor blades, the cascade consisted of seven NACA 65-A506 airfoils with a two inch chord and an aspect ratio of one. The blades were set in the test section at an angle of attack of 15 deg. The test section unit Reynolds number for the evaluation was in excess of two million/foot. Changes to the cascade blade pressure distribution were minimal for moderate average roughness (Ra=24.8 microns) to low average roughness values (Ra=.18 micron), except for pressures near the leading edge which were more pronounced. The pressures near the leading edge which were more pronounced. The pressure distribution for a blade surface roughness of 53.8 microns differed considerable from the baseline case. The cascade test blade experienced laminar flow separation with turbulent reattachment at moderate to low roughness levels, and fully turbulent flow at high roughness levels. The blade suction surface boundary layer thickness increased with roughness values but was most responsive to the transition from laminar to turbulent flow.
Download or read book Effects of Surface Roughness on Pressure Distribution and Boundary Layer Over Compressor Blades at High Reynolds Number in a Two dimensional Cascade written by Larry D. Williams (CAPT, USAF.) and published by . This book was released on 1985 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Two dimensional Low speed Cascade Investigation of NACA Compressor Blade Sections Having a Systematic Variation in Mean line Loading written by John R. Erwin and published by . This book was released on 1953 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comparative tests of blade sections having an isolated airfoil lift coefficient of 1.2 were made for two other blade sections with mean lines having different loading distributions at an inlet angle of 45 degrees with a solidity of 1.5 and at an inlet angle of 60 degrees with a solidity of 1.0.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 836 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Safety and Reliability Theory and Applications written by Marko Cepin and published by CRC Press. This book was released on 2017-06-14 with total page 3668 pages. Available in PDF, EPUB and Kindle. Book excerpt: Safety and Reliability – Theory and Applications contains the contributions presented at the 27th European Safety and Reliability Conference (ESREL 2017, Portorož, Slovenia, June 18-22, 2017). The book covers a wide range of topics, including: • Accident and Incident modelling • Economic Analysis in Risk Management • Foundational Issues in Risk Assessment and Management • Human Factors and Human Reliability • Maintenance Modeling and Applications • Mathematical Methods in Reliability and Safety • Prognostics and System Health Management • Resilience Engineering • Risk Assessment • Risk Management • Simulation for Safety and Reliability Analysis • Structural Reliability • System Reliability, and • Uncertainty Analysis. Selected special sessions include contributions on: the Marie Skłodowska-Curie innovative training network in structural safety; risk approaches in insurance and fi nance sectors; dynamic reliability and probabilistic safety assessment; Bayesian and statistical methods, reliability data and testing; oganizational factors and safety culture; software reliability and safety; probabilistic methods applied to power systems; socio-technical-economic systems; advanced safety assessment methodologies: extended Probabilistic Safety Assessment; reliability; availability; maintainability and safety in railways: theory & practice; big data risk analysis and management, and model-based reliability and safety engineering. Safety and Reliability – Theory and Applications will be of interest to professionals and academics working in a wide range of industrial and governmental sectors including: Aeronautics and Aerospace, Automotive Engineering, Civil Engineering, Electrical and Electronic Engineering, Energy Production and Distribution, Environmental Engineering, Information Technology and Telecommunications, Critical Infrastructures, Insurance and Finance, Manufacturing, Marine Industry, Mechanical Engineering, Natural Hazards, Nuclear Engineering, Offshore Oil and Gas, Security and Protection, Transportation, and Policy Making.
Download or read book Technical Note National Advisory Committee for Aeronautics written by United States. National Advisory Committee for Aeronautics and published by . This book was released on 1958 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technical Note written by and published by . This book was released on 1956 with total page 510 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aeronautical Engineering written by and published by . This book was released on 1971 with total page 580 pages. Available in PDF, EPUB and Kindle. Book excerpt: A selection of annotated references to unclassified reports and journal articles that were introduced into the NASA scientific and technical information system and announced in Scientific and technical aerospace reports (STAR) and International aerospace abstracts (IAA)
Download or read book ASME Technical Papers written by and published by . This book was released on 2000 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Surface Roughness Its Effects on the Performance of a Two Dimensional Compressor Cascade written by J. R. Poulin and published by . This book was released on 1986 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of surface roughness on the losses in the flow through a two-dimensional compressor cascade were studied. The cascade consisted of 7 NACA 65-A506 airfoils with 2-in. chords and aspect ratio of 1. The blades were mounted with a stagger angle of 16 deg, an angle of attack of 15 deg and a solidity of 1.5. The Reynolds number/foot was in excess of 2 million. Three blade configurations were evaluated: one smooth and two with different degrees of roughness applied to the first quarter chord. Hot wire/film anemometers measured velocities and turbulence intensities both in the wake and along the suction surface of the center blade. Surface roughness is shown to increase both boundary layer edge velocities and boundary layer thickness towards the trailing edge while advancing the transition point towards the leading edge. It is also shown to increase wake full thickness, momentum thickness, form factor, and total pressure loss coefficient while decreasing the velocity recovery immediately downstream of the trailing edge. Wake characteristics are most sensitive to an initial increase in roughness but the majority of the changes occur within the first half chord length distance downstream.
Download or read book NASA SP written by and published by . This book was released on 1991 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigation of the Effect of Reynolds Number on Laminar Separation Bubbles on Controlled Diffusion Compressor Blades in Cascade written by David G. Schnorenberg and published by . This book was released on 1996-06-01 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: Detailed experimental investigation of second generation, controlled diffusion, compressor stator blades at an off-design inlet flow angle was performed in a low speed cascade wind tunnel using various experimental procedures. The objective of the study was the characterization of the off- design flow and the detailed investigation of flow separation which occurred near midchord. When it was found that the flow separation behavior was strongly influenced by the Reynolds number, the effect of Reynolds number variation on flow separation was investigated. Surface flow visualization was performed to gain general insight into the flow behavior. Blade surface pressure measurements were obtained using instrumented blades, from which coefficients of pressure were calculated. Laser Doppler velocimetry (LDV) was used to characterize the off-design flow upstream, in the passage between two blades, in the boundary layer on the suction side of the blades, and in the wake region. Overall, good comparisons between blade surface pressure measurements, LDV data and flow visualization were obtained for the separation region. At the highest Reynolds number, separation was turbulent and three dimensional and at the low Reynolds number the separation was predominately laminar and two dimensional.
Download or read book Fluid Mechanics and Thermodynamics of Turbomachinery written by S. Larry Dixon and published by Butterworth-Heinemann. This book was released on 2013-10-10 with total page 557 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fluid Mechanics and Thermodynamics of Turbomachinery is the leading turbomachinery book due to its balanced coverage of theory and application. Starting with background principles in fluid mechanics and thermodynamics, the authors go on to discuss axial flow turbines and compressors, centrifugal pumps, fans, and compressors, and radial flow gas turbines, hydraulic turbines, and wind turbines. In this new edition,more coverage is devoted to modern approaches to analysis and design, including CFD and FEA techniques. Used as a core text in senior undergraduate and graduate level courses this book will also appeal to professional engineers in the aerospace, global power, oil & gas and other industries who are involved in the design and operation of turbomachines. - More coverage of a variety of types of turbomachinery, including centrifugal pumps and gas turbines - Addition of numerical and computational tools, including more discussion of CFD and FEA techniques to reflect modern practice in the area - More end of chapter exercises and in-chapter worked examples
Download or read book Turbojet Engine Noise Reduction with Mixing Nozzle ejector Combinations written by Willard D. Coles and published by . This book was released on 1958 with total page 652 pages. Available in PDF, EPUB and Kindle. Book excerpt: Several noise suppressors consisting of combinations of mixing nozzles and ejectors were tested on two full-scale turbojet engines. Maximum sound pressure level reductions of 12 decibels and sound power level reductions of 8 decibels were obtained. The ejectors provided 3 to 5 decibels of the sound power reduction. The effects of ejector dimensions on noise suppression and engine performance were investigated. Ejector lengths of approximately 2.0 standard nozzle diameters and ejector diameters larger than 1.6 standard nozzle diameters provided the greatest additional noise reduction to that obtained with the mixing nozzles alone. The ejector can restore the static thrust loss caused by use of the mixing nozzle or can provide static-thrust augmentation.
Download or read book Roughness Effects on Compressor Outlet Guide Vanes at High Reynolds Number and High Turning Angle written by David Taylor Genovese and published by . This book was released on 1982 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental investigation of the effects of surface roughness on flow at high Reynolds number over compressor outlet guide vanes at high turning angle in a 2-D cascade was conducted. Two models of roughness were tested: one smoother and one rougher than actual compressor vanes. Four configurations of roughness were evaluated: pressure and suction sides smooth, pressure and suction sides rough, pressure side rough with the suction side smooth and suction side rough with the pressure side smooth.
