National Advisory Committee for Aeronautics (NACA) - Browse

ABOUT BROWSE FEED

Investigation of Power Requirements for Ice Prevention and Cyclical De-Icing of Inlet Guide Vanes with Internal Electric Heaters

Description: An investigation was conducted to determine the electric power requirements necessary for ice protection of inlet guide vanes by continuous heating and by cyclical de-icing. Data are presented to show the effect of ambient-air temperature, liquid-water content, air velocity, heat-on period, and cycle times on the power requirements for these two methods of ice protection. The results showed that for a hypothetical engine using 28 inlet guide vanes under similar icing conditions, cyclical de-icing can provide a total power saving as high as 79 percent over that required for continuous heating. Heat-on periods in the order of 10 seconds with a cycle ratio of about 1:7 resulted in the best over-all performance with respect to total power requirements and aerodynamic losses during the heat-off period. Power requirements reported herein may be reduced by as much as 25 percent by achieving a more uniform surface-temperature distribution. A parameter in terms of engine mass flow, vane size, vane surface temperature, and the icing conditions ahead of the inlet guide vanes.was developed by which an extension of the experimental data to icing conditions and inlet guide vanes, other than those investigated was possible.
Date: December 1, 1950
Creator: VonGlahn, Uwe & Blatz, Robert E.
Partner: UNT Libraries Government Documents Department

Boundary-Layer-Transition Measurements in Full-Scale Flight

Description: Chemical sublimation has been employed for boundary-layer-flow visualization on the wings of a supersonic fighter airplane in level flight at speeds near a Mach number of 2.0. The tests have shown that laminar flow can be obtained over extensive areas of the wing with practical wing-surface conditions. In addition to the flow visualization tests, a method of continuously monitoring the conditions of the boundary layer has been applied to flight testing, using heated temperature resistance gages installed in a Fiberglas "glove" installation on one wing. Tests were conducted at speeds from a Mach number of 1.2 to a Mach number of 2.0, at altitudes from 35,000 feet to 56,000 feet. Data obtained at all angles of attack, from near 0 deg to near 10 deg, have shown that the maximum transition Reynolds number on the upper surface of the wing varies from about 2.5 x 10(exp 6) at a Mach number of 1.2 to about 4 x 10(exp 6) at a Mach number of 2.0. On the lower surface, the maximum transition Reynolds number varies from about 2 x 10(exp 6) at a Mach number of 1.2 to about 8 x 10(exp 6) at a Mach number of 2.0.
Date: July 28, 1958
Creator: Banner, Richard D.; McTigue, John G. & Petty, Gilbert, Jr.
Partner: UNT Libraries Government Documents Department

Aerodynamic characteristics of a 0.04956-scale model of the Convair F-102A airplane at Mach numbers of 1.41, 1.61, and 2.01

Description: Tests have been made in the Langley 4- by 4-foot supersonic pressure tunnel at Mach numbers of 1.41, 1.61, and 2.01 of various arrangements of a 0.04956-scale model of the Convair F-102A airplane with faired inlets. Tests made of the model equipped with a plain wing, a wing with 6.4 percent conical camber, and a wing with 15 percent conical camber. Body modifications including an extended nose, a modified canopy, and extended afterbody fillets were evaluated. In addition, the effects of a revised vertical tail and two different ventral fins were determined. The results indicated that the use of cambered wings resulted in lower drag in the lift-coefficient range above 0.2. This range, however, is above that which would generally be required for level flight; hence, the usefulness of camber might be confined to increased maneuverability at the higher lifts while its use may be detrimental to the high-speed (low-lift) capabilities.
Date: September 30, 1955
Creator: Spearman, M. Leroy & Driver, Cornelius
Partner: UNT Libraries Government Documents Department