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  Partner: UNT Libraries Government Documents Department
 Collection: Technical Report Archive and Image Library
The drag of two streamline bodies as affected by protuberances and appendages

The drag of two streamline bodies as affected by protuberances and appendages

Date: January 1, 1934
Creator: Abbott, Ira H
Description: This report presents the results of wind tunnel tests of two airship models conducted to determine the drag coefficients at zero pitch, and the effect of fins and cars and of flat and streamlined protuberances located at various positions along the hull. During the investigation the stern of one model was rounded off to produce a blunter shape. The extreme range of the Reynolds number based on the over-all length of the models was from 1,300,000 to 33,000,000. At large values of the Reynolds number the streamlined protuberance affected the drag very little, and the additional drag caused by the flat protuberance was less than the calculated drag by the protuberance alone. The fins and cars together increased the bare-hull drag about 20 per cent.
Contributing Partner: UNT Libraries Government Documents Department
Fuselage-drag tests in the variable-density wind tunnel: streamline bodies of revolution, fineness ratio of 5

Fuselage-drag tests in the variable-density wind tunnel: streamline bodies of revolution, fineness ratio of 5

Date: September 1, 1937
Creator: Abbott, Ira H
Description: Results are presented of the drag tests of six bodies of revolution with systematically varying shapes and with a fineness ratio of 5. The forms were derived from source-sink distributions, and formulas are presented for the calculation of the pressure distribution of the forms. The tests were made in the N.A.C.A. variable-density tunnel over a range of values of Reynolds number from about 1,500,000 to 25,000,000. The results show that the bodies with the sharper noses and tails have the lowest drag coefficients, even when the drag coefficients are based on the two-thirds power of the volume. The data shows the most important single characteristic of the body form to be the tail angle, which must be fine to obtain low drag.
Contributing Partner: UNT Libraries Government Documents Department
Interference effects of longitudinal flat plates on low-drag airfoils

Interference effects of longitudinal flat plates on low-drag airfoils

Date: November 1, 1942
Creator: Abbott, Ira H
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Pressure-Distribution Measurements of a Model of a Davis Wing Section with Fowler Flap Submitted by Consolidated Aircraft Corporation

Pressure-Distribution Measurements of a Model of a Davis Wing Section with Fowler Flap Submitted by Consolidated Aircraft Corporation

Date: January 1, 1942
Creator: Abbott, Ira H
Description: Wing pressure distribution diagrams for several angles of attack and flap deflections of 0 degrees, 20 degrees, and 40 degrees are presented. The normal force coefficients agree with lift coefficients obtained in previous test of the same model, except for the maximum lifts with flap deflection. Pressure distribution measurements were made at Reynolds Number of about 6,000,000.
Contributing Partner: UNT Libraries Government Documents Department
Pressure-distribution measurements of two airfoil models with Fowler flaps submitted by Consolidated Aircraft Corporation as alternative wing sections of the XB-32 airplane

Pressure-distribution measurements of two airfoil models with Fowler flaps submitted by Consolidated Aircraft Corporation as alternative wing sections of the XB-32 airplane

Date: January 1, 1942
Creator: Abbott, Ira H
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Tests of four models representing intermediate sections of the XB-33 airplane including sections with slotted flap and ailerons

Tests of four models representing intermediate sections of the XB-33 airplane including sections with slotted flap and ailerons

Date: June 1, 1942
Creator: Abbott, Ira H
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Tests in the variable-density wind tunnel of the NACA 23012 airfoil with plain and split flaps

Tests in the variable-density wind tunnel of the NACA 23012 airfoil with plain and split flaps

Date: January 1, 1939
Creator: Abbott, Ira H & Greenberg, Harry
Description: Section characteristics for use in wing design are presented for the NACA 23012 airfoil with plain and split flaps of 20 percent wing chord at a value of the effective Reynolds number of about 8,000,000. The flap deflections covered a range from 60 degrees upward to 75 degrees downward for the plain flap and from neutral to 90 degrees downward for the split flap. The split flap was aerodynamically superior to the plain flap in producing high maximum lift coefficients and in having lower profile-drag coefficients at high lift coefficients.
Contributing Partner: UNT Libraries Government Documents Department
Flow observations with tufts and lampblack of the stalling of four typical airfoil sections in the NACA variable-density tunnel

Flow observations with tufts and lampblack of the stalling of four typical airfoil sections in the NACA variable-density tunnel

Date: October 1, 1938
Creator: Abbott, Ira H & Sherman, Albert
Description: A preliminary investigation of the stalling processes of four typical airfoil sections was made over the critical range of the Reynolds Number. Motion pictures were taken of the movements of small silk tufts on the airfoil surface as the angle of attack increased through a range of angles including the stall. The boundary-layer flow also at certain angles of attack was indicated by the patterns formed by a suspension of lampblack in oil brushed onto the airfoil surface. These observations were analyzed together with corresponding force-test measurements to derive a picture of the stalling processes of airfoils.
Contributing Partner: UNT Libraries Government Documents Department
Tests of a Highly Cambered Low-Drag-Airfoil Section with a Lift-Control Flap, Special Report

Tests of a Highly Cambered Low-Drag-Airfoil Section with a Lift-Control Flap, Special Report

Date: December 1, 1942
Creator: Abbott, Ira H. & Miller, Ralph B.
Description: Tests were made in the NACA two-dimensional low turbulence pressure tunnel of a highly cambered low-drag airfoil (NACA 65,3-618) with a plain flap designed for lift control. The results indicate that such a combination offers attractive possibilities for obtaining low profile-drag coefficients over a wide range of lift coefficients without large reductions of critical speed.
Contributing Partner: UNT Libraries Government Documents Department
Summary of Airfoil Data

Summary of Airfoil Data

Date: January 1, 1945
Creator: Abbott, Ira H; Von Doenhoff, Albert E & Stivers, Louis, Jr
Description: The historical development of NACA airfoils is briefly reviewed. New data are presented that permit the rapid calculation of the approximate pressure distributions for the older NACA four-digit and five-digit airfoils by the same methods used for the NACA 6-series airfoils. The general methods used to derive the basic thickness forms for NACA 6 and 7-series airfoils together with their corresponding pressure distributions are presented. Detail data necessary for the application of the airfoils to wing design are presented in supplementary figures placed at the end of the paper. The report includes an analysis of the lift, drag, pitching-moment, and critical-speed characteristics of the airfoils, together with a discussion of the effects of surface conditions. Available data on high-lift devices are presented. Problems associated with lateral-control devices, leading-edge air intakes, and interference are briefly discussed, together with aerodynamic problems of application. (author).
Contributing Partner: UNT Libraries Government Documents Department