Download or read book Aerodynamic Analysis of Blunt Trailing Edge Airfoils a Micro based Load Control System written by Kevin James Standish and published by . This book was released on 2003 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aerodynamic Coefficients and Pressure Distribution on Blunt Trailing edge Airfoils written by Allen Soong Yaplee and published by . This book was released on 1958 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Wind Tunnel and Numerical Analysis of Thick Blunt Trailing Edge Airfoils written by Anthony William McLennan and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Two-dimensional aerodynamic characteristics of several thick blunt trailing edge airfoils are presented. These airfoils are not only directly applicable to the root section of wind turbine blades, where they provide the required structural strength at a fraction of the material and weight of an equivalent sharp trailing edge airfoil, but are also applicable to the root sections of UAVs having high aspect ratios, that also encounter heavy root bending forces. The Reynolds averaged Navier-Stokes code, ARC2D, was the primary numerical tool used to analyze each airfoil. The UCD-38-095, referred to as the Pareto B airfoil in this thesis, was also tested in the University of California, Davis Aeronautical Wind Tunnel. The Pareto B has an experimentally determined maximum lift coefficient of 1.64 at 14 degrees incidence, minimum drag coefficient of 0.0385, and maximum lift over drag ratio of 35.9 at a lift coefficient of 1.38, 10 degrees incidence at a Reynolds number of 666,000. Zig-zag tape at 2% and 5% of the chord was placed on the leading edge pressure and suction side of the Pareto B model in order to determine the aerodynamic performance characteristics at turbulent flow conditions. Experimental Pareto B wind tunnel data and previous FB-3500-0875 data is also presented and used to validate the ARC2D results obtained in this study. Additionally MBFLO, a detached eddy simulation Navier-Stokes code, was used to analyze the Pareto B airfoil for comparison and validation purposes.

Download or read book Experimental Investigation Into the Effectiveness of a Microtab Aerodynamic Load Control System written by Jonathon Paul Baker and published by . This book was released on 2005 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Unsteady Computational Investigations of Deploying Load control Microtabs written by Raymond Chow and published by . This book was released on 2006 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Theoretical Aerodynamic Characteristics of Sharp and Circularly Blunt wedge Airfoils written by Joseph W. Cleary and published by . This book was released on 1964 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerical solutions of the pressure distributions of blunt wedges for Mach numbers of 10 and ∞ are presented. The pressure distributions have been integrated to provide the inviscid lift, drag, and pitching-moment coefficients of any circularly blunt-wedge airfoil. The effects of varying surface angle, nose bluntness, and gas specific-heat ratio are discussed. A hypersonic wedge theory, derived from explicit oblique-shock equations, is introduced and is shown to predict accurately the loading and aerodynamic characteristics of surfaces with attached shocks. With appropriate account taken for nose bluntness, the theory is shown to be applicable to blunt airfoils.

Download or read book Characterization and Estimation of Three dimensional Structure in Unforced and Forced Blunt Trailing Edge Wake Flows written by Heather Clark and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Blunt trailing edge airfoils offer structural and aerodynamic advantages in modern wind turbine and aircraft applications. However, penalties are introduced concurrently by vortex shedding at separation. In particular, the adverse effects of increased drag and unsteady loading motivate the development of a control strategy for the blunt trailing edge wake. Closed-loop control is pursued for its potentially greater effectiveness and efficiency, relative to open-loop forcing. Toward this aim, the thesis addresses the need for estimation of the state from limited measurements. The wake of a blunt trailing edge body is investigated experimentally through simultaneous measurements of velocity and the spanwise distribution of fluctuating surface pressure. Passive forcing is implemented with an array of vortex generators that are arranged according to the characteristic wavelength of the dominant small-scale instability. The guiding considerations for the analysis and discussion are physical characterization and the development of estimation strategies based on surface pressure. Joint examination of the measured variables through reduced-order modelling, wavelet analysis, and conditional averaging yields insight regarding the unsteady, three-dimensional nature of the flow. The investigation of forcing is focused upon the influence of the perturbation on the surface pressure and the performance of estimation models in the modified wake. It is found that low-frequency amplitude modulation of the pressure results from variation of both the magnitude of velocity fluctuations and the vortex formation length. The forcing regularizes the shedding in time and space, as evidenced by the attenuated modulation and enhanced spanwise coherence of the amplitude and phase. Examination of this behaviour confirms the connection between amplitude modulation and vortex dislocations in bluff body wakes. Several properties of the estimation approaches hold in general. It is shown that the phase is captured well, while the nonlinear relationship between the pressure and velocity presents a challenge for accurate estimation of the amplitude. Although the small-scale structure remains unobservable from the pressure sensing scheme, the large-scale spanwise variation of the wake is reproduced with equal fidelity by estimation models constructed in two orthogonal planes. The increased organization with forcing results in reduced estimation error, relative to the unforced case.

Download or read book Navier Stokes Analysis of Blunt Trailing Edge Airfoils written by Sharon K. Stanaway 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 An Aerodynamic Analysis Computer Program and Design Notes for Low Speed Wing Flap Systems written by and published by . This book was released on 1983 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Boundary layer Transition Prediction for Reynolds averaged Navier Stokes Methods written by Edward Anthony Mayda and published by . This book was released on 2007 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analysis of Divergent Trailing Edge Supercritical Airfoils Using Computational Aerodynamics written by Christopher A. Konings and published by . This book was released on 1993 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Euler Zonal Method for Blunt Trailing Edge Airfoils written by Marcia Fordham Herndon and published by . This book was released on 1992 with total page 80 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 1991 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Flatback Airfoils written by Camille Nadine Metzinger and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A two-dimensional experimental examination of the effect of splitter plate length on both aerodynamic performance and vortex shedding behavior as well as an initial evaluation of the shedding coherence for a flatback airfoil is presented. The FB-3500-1750 is a thick airfoil with a blunt trailing edge (also called a flatback airfoil) designed for the inboard region of wind turbine blades. Its maximum thickness is 35% of the airfoil chord, with a trailing edge thickness (t[subscript TE]) of 17.5%. In the present study, the FB-3500-1750 airfoil was tested in the University of California, Davis aeronautical wind tunnel at a chord Reynolds number of 666,000. Drag reductions of at least 27% from the baseline were observed with the inclusion of a splitter plate length of 50% t[subscript TE]. Additionally, increasing splitter plate length was shown to continue to decrease the base drag. Maximum lift reductions and earlier stall angles were also observed with increasing splitter plate length though with the 50% t[subscript TE] configuration, the loss in maximum lift coefficient was limited to 5%. Examining vortex shedding behavior, increases in the nondimensional shedding frequency, Strouhal number, were seen with increasing splitter plate length for the measured range. Lastly, for the baseline FB-3500-1750 airfoil, the spanwise correlation length of the vortex shedding was determined as 4-5.5 t[subscript TE] for all the angle of attack and transition (fixed and free) configurations evaluated.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design and Aerodynamic Analysis of an Airfoil with a Bioinspired Leading Edge Device for Stall Mitigation at Low Reynolds Number Operation written by Boris Atanasov Mandadzhiev and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Unsteady Airfoil Flow Control Via a Dynamically Deflected Trailing edge Flap written by Panayiote Gerontakos and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "The control of the flow around a harmonically oscillating NACA 0015 airfoil via a dynamically deflected simply-hinged trailing-edge flap was investigated experimentally at a Reynolds number of 2.46 x 105 by using a combination of techniques, including surface pressure measurements, hot-wire wake velocity surveys and particle image velocimetry flowfield measurements. The tests were conducted under deep-stall conditions, with special attention being focused on identifying the changes in the flow structures that led to the observed modified aerodynamic load characteristics, and on the evaluation of the effects of the prescheduled trapezoidal flap motion profile. In addition, light-stall and attached-flow oscillations were also considered, as were static flap deflections and higher harmonic flap motions. The results indicate that a trailing-edge flap imposed an effective camber in the trailing-edge region, and was highly effective in the control of the aerodynamic loads. This was achieved in large part by the manipulation of the lower flap surface pressure distribution via changes to the windward-side flow stream, and was unaffected by the state of the flow above the airfoil. The leading-edge vortex, the predominant flow structure over the airfoil, was only marginally affected in its strength and initiation. The results also revealed that both the flap angle and deflection rate contributed to the above observations, and that the active motion was crucial in preventing the flow separation observed over the lower flap surface for an equivalent static flap, which would have hindered its performance. Furthermore, control was limited to the duration of the flap motion, and, in general, no effect on the flow or aerodynamic loads was observed while the flap was withdrawn to its initial undeflected position. The detailed parametric study showed the characteristics of the flap motion profile to be highly influential on the degree of control. In the application of an optimum flap motion schedule to dynamic stall, the severe nose-down pitching moment decreased by 40%, the performance ratio improved by 30%, and the aerodynamic damping became positive and increased four-fold; this was, however, accompanied by a 20% reduction in the maximum lift."--