Download or read book Effects of Free stream Turbulence on Blade Performance in a Compressor Cascade written by B. J. Evans and published by . This book was released on 1971 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Preliminary Report Into the Effects of Free stream Turbulence on Blade Performance in a Compressor Cascade written by Bernard John Evans and published by . This book was released on 1970 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Surface Roughness Freestream Turbulence and Incidence Angle on the Performance of a 2 D Compressor Cascade written by W. C. Elrod and published by . This book was released on 1990 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of surface roughness, freestream turbulence, and incidence angle on the performance of a two-dimensional compressor cascade were investigated. The test section consisted of seven NACA 65-A506 airfoils arranged in a linear cascade. Four different surface roughness conditions were applied to the first 25 percent chord on the suction surface of each of the five middle blades in the cascade. Freestream turbulence levels of approximately one and seven percent were used. Incidence angles of −3, zero and +3 degrees were investigated. Of the three parameters tested, freestream turbulence exerted the largest influence on blade performance. The total pressure loss coefficient increased with increased roughness and was reduced for large turbulence. Changes in flow incidence had a lesser effect on the performance of the blade.
Download or read book The Effects of Incidence Angle and Free Stream Turbulence on the Performance of a Variable Geometry Two Dimensional Compressor Cascade at High Reynolds Numbers written by Edward M. Poniatowski and published by . This book was released on 1988 with total page 321 pages. Available in PDF, EPUB and Kindle. Book excerpt: For this investigation, a seven-blade cascade of NACA 65-A506 airfoils with two inch chord, aspect ration of one, and solidity of 1.5 was used. This cascade used porous side wall suction to establish two-dimensional flow conditions. Flow Unit Reynolds numbers exceeding 2.5 million foot, and average free stream turbulence levels of 1% and 7% were used. Cascade geometry was varied in a manner similar to that used in current variable stator designs: maintaining axial direction and blade spacing constant, while varying incidence angle, stagger angle, and angle of attack. Incidence angles of -3, 0, and +3 deg. were investigated. Total pressure loss coefficient decreases through the cascade and may increase in the wake as incidence angle or free stream turbulence increase. The change in loss coefficient with increasing incidence was determined to be insignificant when compared with the change as a result of increased free stream turbulence. Blade suction surface pressure coefficients decrease sharply along the first 30% chord as incidence increases. The suction surface pressure coefficients show a uniform increase across the blade center span with additional free stream turbulence. Increases in incidence and free stream turbulence result in thicker boundary layers and suggest both earlier transition and intermittent separation on the forward half of the blade. Evidence also suggests that the location of the minimum loss incidence angle may change with additional free stream turbulence. Keywords: Compressor blades; Pressure distribution, Cascades fluid dynamics; Cascade structures; Boundary layer, Theses. (edc).
Download or read book Experimental Investigation Into the Effects of Riblets on Compressor Cascade Performance written by James A. Rothenflue and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of adding riblets to the blades of a subsonic, linear compressor cascade were investigated at the Air Force Institute of Technology. Three blade configurations were tested, including a set of unmodified NACA 64- A905 series blades, a set with riblets applied to the suction surface, and a set with riblets on the pressure surface. Performance was evaluated over a wide range of Reynolds numbers, and at low and high free stream turbulence levels. Cascade performance was evaluated in terms of total pressure loss coefficient, turning angle, and static pressure rise. No riblet configuration offered robust cascade performance improvements; however, performance was significantly enhanced under certain specific conditions. Riblets also degraded cascade performance at other conditions.
Download or read book Roughness Effects on Compressor Blade Performance in Cascade at High Reynolds Number written by F. J Tanis (Jr) and published by . This book was released on 1983 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental investigation of the effect of roughness on compressor blade performance in cascade at high Reynolds numbers was performed. A 7-blade cascade of NACA 64-A905 blades with a chord of 2 in. and aspect ratio of 1 was tested in linear cascade. The blades were mounted with a stagger angle of 31 deg and angle of attack of 15 deg. Spacing between blades was 1.33 in. which gave a solidity of 1.5. This study was divided into two parts: to determine the importance of the location of roughness on blade performance; and to determine how the degree of roughness affects blade performance. The velocity and turbulence intensity profiles of the flow region downstream of the center blade and the non-dimensional total pressure loss parameter omega bar were used to evaluate blade performance. Hot wire anemometry measured velocity and turbulence intensity profiles downstream of the blade. Measured exit velocity and static pressure were used to derive the exit total pressure. Roughness located near the leading edge of the blade caused the greatest impact on omega bar and the velocity and turbulence intensity profiles. Changes in magnitude of roughness did not affect blade performance until a threshold was exceeded; then performance decreased rapidly.
Download or read book Numerical Simulation of Unsteady Flows and Transition to Turbulence written by O. Pironneau and published by Cambridge University Press. This book was released on 1992-07-31 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt: The workshop concentrated on the following turbulence test cases: T1 Boundary layer in an S-shaped duct; T2 Periodic array of cylinders in a channel; T3 Transition in a boundary layer under the influence of free-stream turbulence; T4 & T5: Axisymmetric confined jet flows.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Impact of Free stream Turbulence Intensity on the Endwall Region of Low Pressure Turbine Blades written by Molly Hope Donovan and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbomachinery components, such as the low pressure turbine, are highly complex rotating machines, therefore, conducting fundamental fluid mechanics studies in them is exceedingly difficult. For this reason, testing is generally completed in facilities such as linear cascades, like the one present in the Low Speed Wind Tunnel Facility at AFRL, which typically utilize a low freestream turbulence intensity, when in reality, the freestream turbulence intensity in a full, rotating low pressure turbine is likely much higher. Slightly elevating the freestream turbulence intensity (e.g., 3%) typically improves the Reynolds-lapse characteristics of a blade profile by affecting the transition process, reducing the detrimental effects of laminar boundary layer separation, and shifting the knee in the loss curve. Front loaded blades are more resistant to separation, however, they can experience high losses in the endwall region due to the complex vortical structures present. Therefore, a better understanding whether high levels of freestream turbulence intensity will increase the overall losses generated in the passage is important. An intial study with a jet based active grid was completed on the L2F blade. Based of the insight gained from that study, a new mechanical agitator based active grid was implemented into a linear cascade of L3FHW-LS blades in order to more effectively study how elevated FSTI impacts the endwall flow behavior and loss production. Coefficient of pressure measurements, three planes of SPIV, two additional planes of flow visualization, and three planes of total pressure loss measurements were collected. Impacts of incoming turbulence on the endwall losses as well as the endwall flow structures were assessed.
Download or read book Cascade Aerodynamics written by J. P. Gostelow and published by Pergamon. This book was released on 1984 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt: Good,No Highlights,No Markup,all pages are intact, Slight Shelfwear,may have the corners slightly dented, may have slight color changes/slightly damaged spine.
Download or read book Aerodynamic Design of Axial flow Compressors written by Lewis Research Center and published by . This book was released on 1965 with total page 542 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Aerodynamic Design of Axial Flow Compressors written by Robert O. Bullock and published by . This book was released on 1965 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Role of Free Stream Turbulence and Blade Surface Conditions on the Aerodynamic Performance of Wind Turbine Blades written by Victor Hugo Maldonado and published by . This book was released on 2012 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Applied Mechanics Reviews written by and published by . This book was released on 1970 with total page 772 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA SP written by and published by . This book was released on 1992 with total page 654 pages. Available in PDF, EPUB and Kindle. Book excerpt:
