![]() At high angles of attack, the NACA 64-2 airfoils had improved aerodynamic performance in rain conditions due to an apparent reduction of the boundry layer separation. The Wortmann section had the greatest overall lift degradation and the NACA 64-210 airfoil had the smallest. At low angles of attack, the lift degradation in wet conditions varied significantly between the airfoils. Lift and drag were measured in dry and wet conditions, a variety of flow visualization techniques were employed, and a computational code which predicted airfoil boundary layer behavior was used. Wind tunnel experiments were conducted on Wortmann FX67-K170, NACA 0012, and NACA 64-210 airfoils at rain rates of 1000 mm/hr and Reynolds numbers of 310,000 to compare the aerodynamic performance degradation of the airfoils and to attempt to identify the various mechanisms which affect performance in heavy rain conditions. ![]() The data are presented in the form of pressure-distribution diagrams and as graphs of calculated coefficients for the airfoil-and-flap combination and for the flap alone.Īn experimental low Reynolds number comparison of a Wortmann FX67-K170 airfoil, a NACA 0012 airfoil and a NACA 64-210 airfoil in simulated heavy rain ![]() A test installation was used in which the airfoil was mounted horizontally in the wind tunnel between vertical end planes so that two-dimensional flow was approximated. The pressures were measured on the upper and lower surfaces at one chord section on both the main airfoil and on the flap for several different flap deflections and at several angles of attack. Report presents the results of pressure-distribution tests of an NACA 23012 airfoil with an NACA 23012 external airfoil flap made in the 7 by 10-foot wind tunnel. Pressure distribution over an NACA 23012 airfoil with an NACA 23012 external- airfoil flap Qualitative explanations in terms of flow behavior are advanced for the observed types of scale effect. The characteristics of an airfoil with a split flap were determined in one instance, as was the effect of surface roughness. The airfoils selected represent sections having variations in the airfoil thickness, thickness form, and camber. Also presented are data from NACA Technical Report 824 for the same airfoils at Reynolds numbers of 3.0 x 10sub 6, 6.0 x 10sub 6, and 9.0 x 10sub 6. Results are presented of an investigation made to determine the two-dimensional lift and drag characteristics of nine NACA 6- series airfoil section at Reynolds numbers of 15.0 x 10sub 6, 20.0 x 10sub 6, and 25.0 x 10sub 6. Loftin, Laurence K, Jr Bursnall, William J The effects of variations in Reynolds number between 3.0 x 10sub 6 and 25.0 x 10sub 6 upon the aerodynamic characteristics of a number of NACA 6- series airfoil sections Each airfoil data bank computer code was written to be used on the Amdahl Computer system, which is IBM compatible and uses Fortran. The various component of each computer code, the source of the data used to create the airfoil data bank, the limitations of each data bank, program listing, and a sample case with its associated input-output are described. The families chosen consisted of the Clark-Y, NACA 16 series, and NACA 4 digit series airfoils. Realizing the need for such data, a study was initiated to provide airfoil data banks for three commonly used airfoil families in propeller design and analysis. Inherent in the majority of the theoretical performance models to date is the need for airfoil data banks which provide lift, drag, and moment coefficient values as a function of Mach number, angle-of-attack, maximum thickness to chord ratio, and Reynolds number. With the renewed interest in propellers as means of obtaining thrust and fuel efficiency in addition to the increased utilization of the computer, a significant amount of progress was made in the development of theoretical models to predict the performance of propeller systems. Sample calculations for an NACA 63(2)-015 airfoil showed an annual energy output increase of 17-27 percent, depending on rotor solidity, compared to an NACA 0015 airfoil.Īerodynamic data banks for Clark-Y, NACA 4-digit and NACA 16- series airfoil families Results indicated that NACA 6- series airfoils yield peak power coefficients as great as NACA 4-digit airfoils and have broader and flatter power coefficient-tip speed ratio curves. Performance estimates were made using a blade element/momentum theory approach. Ten different airfoils, having thickness-to-chord ratios of 12, 15, and 18 percent, were studied. Analysis was limited to curved-bladed machines having rotor solidities of 7-21 percent and operating at a Reynolds number of 3 x 10 to the 6th. The aerodynamic efficiency of Darrieus wind turbines as effected by blade airfoil geometry was investigated. Comparison of NACA 6- series and 4-digit airfoils for Darrieus wind turbines
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