The method uses a two-dimensional, implicit, conservative finite difference scheme for solving the compressible Navier-Stokes equations. N.Ī full Navier-Stokes solver has been used to model transonic flow over three airfoil sections. The data may also be applied to the design of air brakes and spoilers.Īnalysis of viscous transonic flow over airfoil sections The results provide fundamental data on which to base the prediction of the effects of actual short-span protuberances. The effects of variations of the fore-and-aft position, height, and shape of the protuberance were measured by determining how the airfoil section characteristics were affected by the addition of the various protuberances extending along the entire span of the airfoil. The drag and interference caused by protuberance from the surface of an airfoil have been determined in the NACA variable-density wind tunnel at a Reynolds number approximately 3,100,000. New airfoils sections are proposed and analyzed for straight-bladed turbine.Īirfoil section characteristics as affected by protuberances In order to choose appropriate value of zero-lift-drag coefficient in calculation, an analytical expression is introduced as function of chord-radius ratio and Reynolds numbers. The model is also adapted to the vertical Darrieus turbine for the performance prediction of the machine. The blade section aerodynamics characteristics are determined from turbomachines cascade model. New airfoil sections for straight bladed turbineĪ theoretical investigation of aerodynamic performance for vertical axis Darrieus wind turbine with new airfoils sections is carried out. These results are briefly presented in this extended abstract. Preliminary data are also acquired for periodically pitched airfoil. Data include mean velocity, streamwise vorticity as well as various turbulent stresses. Flow visualization pictures as well as detailed cross-sectional properties areobtained at various streamwise locations using hot-wire anemometry. Initially, data for stationary airfoil held fixed at various angles-of-attack are gathered. Zaman, Khairul Fagan, Amy Mankbadi, MinaĪn experimental investigation of tip vortex flow from a NACA0012 airfoil, pitched periodically at various frequencies, is conducted in a low-speed wind tunnel. The inboard section may be configured with a tapered cross-sectional area to support the outboard section.Įxperimental Study of Tip Vortex Flow from a Periodically Pitched Airfoil Section The outboard section may be configured to provide a tip having adequate thickness and may extend radially inward from the tip with a generally constant cross-sectional area. In future, this airfoil database will be used to study novel concepts for aircraft engines.Turbine airfoil having outboard and inboard sectionsĪ turbine airfoil usable in a turbine engine and formed from at least an outboard section and an inboard section such that an inner end of the outboard section is attached to an outer end of the inboard section. The benefit of using airfoils optimized for their specific purpose over having generic airfoil shapes is discussed as well. The database offers a wide variety of airfoils for different applications.Īirfoils for sub- and supersonic inflow are covered as well as airfoils suited for placement at hub or casing. The optimized geometries of four of the airfoils under investigation are found in the appendix. To verify the optimization strategy, it is tested on a set of existing compressor airfoils. The solver is well established among industry and research and it is validated to a high degree by experiments. Design and off-design performance is evaluated with the blade-to-blade flow solver MISES. The target is to find airfoil shapes that have low losses and ensure stable operation over wide incidence ranges. To fill this seven-dimensional space, a large number of airfoils is generated by means of numerical optimization at discrete points in this space. These constraints include limitations for profile area depending on inlet Mach number and limits for axial Mach number. Additional constraints are imposed to ensure that feasible airfoils exist for each set of requirements. The database is structured in seven dimensions, denominated as 'design requirements': blade stagger angle, pitch-chord ratio, profile area and the following design point properties: inlet Mach number, Reynolds number, streamtube contraction and aerodynamic loading. This airfoil family is generated by filling a database with optimized airfoil shapes. This paper aims to generate a highly versatile compressor airfoil family that covers most applications in the core compression system of aircraft engines and stationary gas turbines. Ensuring a high degree of commonality among a range of products can dramatically decrease development costs.
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