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  Partner: UNT Libraries Government Documents Department
 Serial/Series Title: NACA Technical Notes
 Collection: Technical Report Archive and Image Library
Wind-tunnel tests of a full-scale helicopter rotor with symmetrical and with cambered blade sections at advance ratios from 0.3 to 0.4

Wind-tunnel tests of a full-scale helicopter rotor with symmetrical and with cambered blade sections at advance ratios from 0.3 to 0.4

Date: September 1, 1958
Creator: Mccloud, John L , III & Mccullough, George B
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Wind-tunnel tests of a Hall high-life wing

Wind-tunnel tests of a Hall high-life wing

Date: May 1, 1932
Creator: Weick, Fred E & Sanders, Robert
Description: Wind-tunnel tests have been made to find the lift, drag, and center-of-pressure characteristics of a Hall high-lift wing model. The Hall wing is essentially a split-flap airfoil with an internal air passage. Air enters the passage through an opening in the lower surface somewhat back of and parallel to the leading edge, and flows out through an opening made by deflecting the rear portion of the under surface downward as a flap. For ordinary flight conditions the front opening and the rear flap can be closed, providing in effect a conventional airfoil (the Clark Y in this case). The tests were made with various flap settings and with the entrance to the passage both open and closed. The highest lift coefficient found, C(sub L) = 2.08, was obtained with the passage closed.
Contributing Partner: UNT Libraries Government Documents Department
Wind-tunnel tests of a wing with a trailing-edge auxiliary airfoil used as a flap

Wind-tunnel tests of a wing with a trailing-edge auxiliary airfoil used as a flap

Date: January 1, 1935
Creator: Noyes, Richard W
Description: This report gives the characteristics of a wing with an auxiliary airfoil mounted near its trailing edge and used as a flap. The tests were made with a 10 by 60 inch Clark Y main airfoil and an NACA 0012 flap having a chord equal to 15 percent of the main wing chord. The axis of the flap in all cases was on the flap chord and 20 percent back from its leading edge. The optimum location of the flap axis relative to the main wing for maximum lift was found to be 1.25 percent of the main wing chord behind the trailing edge and 2.5 percent below the chord. In this position C(sub L max) was increased from 1.250 (for the plain wing) to 1.810 at 45 degrees deflection of the flap and C(sub D min) was decreased form 0.0155 to 0.0146 at minus 5 degrees deflection, the coefficient in each case being based on the sum of the flap and wing areas. No serious adverse change in lateral stability was found to result from the use of the flap in the optimum position.
Contributing Partner: UNT Libraries Government Documents Department
Wind tunnel tests of an NACA 23021 airfoil equipped with a slotted extensible and a plain extensible flap

Wind tunnel tests of an NACA 23021 airfoil equipped with a slotted extensible and a plain extensible flap

Date: November 1, 1940
Creator: Swanson, Robert S & Harris, Thomas A
Description: An investigation has been made in the NACA 7- by 10-foot wind tunnel of a large chord NACA 23021 airfoil equipped with two arrangements of a completely extended 15 percent chord extensible flap. One of the flaps had a faired juncture, without a gap; the other was provided with a slot between the trailing edge of the airfoil and the nose of the flap. The results showed that the basic airfoil gave the lowest profile-drag coefficients over the low lift range, the airfoil with the plain extensible flap gave the lowest profile-drag coefficients over the moderate lift range, and the airfoil with the slotted extensible flap gave the lowest profile-drag coefficients over the high lift range. The airfoil with the slotted extensible flap had the same maximum lift at a flap deflection of 25 degrees as the airfoil with the plain extensible flap had at a flap deflection of 60 degrees. The results of comparisons of the airfoil pitching-moment coefficients obtained with the two types of flap are dependent upon the basis chosen for comparison. Complete aerodynamic section characteristics are presented for the various flap deflections for both flap arrangements in the completely extended portion.
Contributing Partner: UNT Libraries Government Documents Department
Wind-tunnel tests of carburetor-intake rams

Wind-tunnel tests of carburetor-intake rams

Date: January 1, 1938
Creator: Highley, Frank H
Description: An investigation was conducted in the NACA 20-foot wind tunnel of the ramming effect of three general types of carburetor intake rams for radial engines, namely, the internal constant area type, the external constant area type, and the external expanding type. The rams were installed on a radial air- cooled engine nacelle, and tests were made with and without the propeller operating. The results indicated that the external types having entrances near the front of the engine cowling gave the greatest ramming effect. The propeller increased the ramming effect for the external types. From considerations of the ramming effect, the best entrance location for the external types was close to the nose of the engine cowling. For the internal type, the best location was in a plane perpendicular to the propeller shaft and immediately forward of the engine cylinders.
Contributing Partner: UNT Libraries Government Documents Department
Wind tunnel tests of five strut sections in yaw

Wind tunnel tests of five strut sections in yaw

Date: November 1, 1923
Creator: Warner, Edward P
Description: In the first series of wind tunnel tests, the drag and cross wing force of all the struts were measured at a wind speed of 30 mph and at angles of yaw from 0 degrees to 20 degrees. To determine the magnitude of the VL effect, each strut was tested at zero yaw and at a series of speeds ranging from 15 to 38 mph. Although designed as fairings for cables, part of these sections gave such high crosswind forces that they seemed to have possibilities as airfoils. Therefore, the lift (identical with the crosswind force) and drag coefficients were recalculated for four sections on the basis of broadside area to make them comparable with wing coefficients. The general conclusion that the best fineness ratio for a strut is a function of the Reynolds number, decreasing steadily as that quality increases, has of course been reached many times, both by theory and experiment. It was confirmed here once more, and the effect of form on sensitiveness to VL is also strikingly shown. It seems probable that this effect of form is largely due to interaction between the nose and tail, and to the influence which the form of the nose ...
Contributing Partner: UNT Libraries Government Documents Department
Wind tunnel tests of fuselages and windshields

Wind tunnel tests of fuselages and windshields

Date: September 1, 1925
Creator: Warner, Edward P
Description: The tests described herein were made in 1918, in the old four-foot wind tunnel at the Massachusetts Institute of Technology and at the request of the Engineering Division of the U.S. Army Air Service. The results were given circulation only in official circles at that time. The interest of the work appears sufficient to justify its wider distribution even at this very late date.
Contributing Partner: UNT Libraries Government Documents Department
Wind-tunnel tests of several forms of fixed wing slot in combination with a slotted flap on an N.A.C.A. 23012 airfoil

Wind-tunnel tests of several forms of fixed wing slot in combination with a slotted flap on an N.A.C.A. 23012 airfoil

Date: April 1, 1939
Creator: Bamber, M J
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Wind-tunnel tests of the Fowler variable-area wing

Wind-tunnel tests of the Fowler variable-area wing

Date: May 1, 1932
Creator: Weick, Fred E & Platt, Robert C
Description: The lift, drag, and center of pressure characteristics of a model of the Fowler variable-area wing were measured in the NACA 7 by 10 foot wind tunnel. The Fowler wing consists of a combination of a main wing and an extension surface, also of airfoil section. The extension surface can be entirely retracted within the lower rear portion of the main wing or it can be moved to the rear and downward. The tests were made with the nose of the extension airfoil in various positions near the trailing edge of the main wing and with the surface at various angular deflections. The highest lift coefficient obtained was C(sub L) = 3.17 as compared with 1.27 for the main wing alone.
Contributing Partner: UNT Libraries Government Documents Department
Wind-tunnel tests of wing flaps suitable for direct control of glide-path angle

Wind-tunnel tests of wing flaps suitable for direct control of glide-path angle

Date: January 1, 1936
Creator: Weick, Fred E
Description: Preliminary tests have been made for the purpose of obtaining a flap arrangement suitable for direct and immediate control of the steepness of the glide path of an airplane, a use for which present flaps are not satisfactory. An attempt has been made to develop a flap giving a reasonably high maximum lift coefficient with relatively low deflection and maintaining this value of the maximum lift coefficient with a large increase of deflection, the increase in deflection being accompanied by a large increase in drag. An arrangement was found that gave a maximum lift coefficient of approximately 1.90 for all flap deflections between 25 and 80 degrees, within which range the drag of the wing increased regularly to a large value.
Contributing Partner: UNT Libraries Government Documents Department