This system will be undergoing maintenance Friday, March 31 from 9:00 AM to 10:00 AM CDT.

UNT Libraries Government Documents Department - Browse


Pressure lag in tubing used in flight research

Description: Tests described in this report were undertaken to obtain a quantitative measure of the pressure lag in typical pressure-tubing systems used by the Ames Aeronautical Laboratory in flight research investigations. Lag measurements were made with both single-direction and oscillating pressure changes. Single-direction pressure changes were investigated to determine if the lag in orifice-pressure lines and in the research airspeed and altitude measuring systems of pursuit-type airplane undergoing flight tests was sufficient to cause an appreciable error in the record of a sudden pressure change. Oscillating pressure changes were investigated with particular reference to the accuracy of pressure peaks in pressure-distribution measurements during the time of buffeting conditions as found in stalls. (author).
Date: January 1, 1945
Creator: Turner, Howard L. & Rathert, George A., Jr.
Item Type: Report

Analysis of V-G Records from the SNB-1 Airplane

Description: Availability data obtained on SNB-1 trainer-class airplanes were analyzed and results presented as flight envelopes which predict occurrences of large values of air speed and acceleration. Comparison is made with SNJ-4 trainer-class airplane data analyzed by the same method. It is concluded that flight envelopes are satisfactory; that the two types show large differences in flight loads and speeds experience; and that SNB-1 will seldom, if ever, exceed design limit load factor and restricted speed, which SNJ-4 can be expected to exceed design-limit load factor and restricted speed in a very small number of flight hours.
Date: July 1946
Creator: Meadows, May T. & Walker, Walter G.
Item Type: Report

Performance Characteristics of an Aircraft Engine with Exhaust Turbine Supercharger, Special Report

Description: The Pratt and Whitney Aircraft company and the Naval Aircraft Factory of the United States Navy cooperated in a laboratory and flight program of tests on an exhaust turbine supercharger. Two series of dynamometer tests of the engine super-charger combination were completed under simulated altitude conditions. One series of hot gas-chamber tests was conducted by the manufacturer of the supercharger. Flight demonstrations of the supercharger installed in a twin-engine flying boat were terminated by failure of the turbine wheels. The analysis of the results indicated that a two-stage supercharger with the first-stage exhaust turbine driven will deliver rated power for a given indicated power to a higher altitude, will operate more efficiently, and will require simpler controls than a similar engine with the first stage of the supercharger driven from the crankshaft through multispeed gears.
Date: May 1, 1941
Creator: Lester, E. M. & Paulson, V. A.
Item Type: Report

The Effect of Surface Irregularities on Wing Drag. IV - Manufacturing Irregularities, 5, Manufacturing Irregularities

Description: Tests were made in the NACA 8-foot high speed wind tunnel of a metal-covered, riveted, 'service' wing of average workmanship to determine the aerodynamic effects of the manufacturing irregularities incident to shop fabrication. The wing was of 5-foot chord and of NACA 23012 section and was tested in the low-lift range at speeds from 90 to 450 miles per hour corresponding to Reynolds numbers from 4,000,000 to 18,000,000. At a cruising condition the drag of the service wing was 46% higher than the drag of a smooth airfoil, whereas the drag of an accurately constructed airfoil having the same arrangement of 3/32-inch brazier-head rivets and lap joints showed a 29% increase. The difference, or 17% of the smooth-wing drag, is apparently the drag caused by the manufacturing irregularities: sheet waviness, departures from true profile, and imperfect laps. the service wing, for one condition at least, showed a drag increase due to compressibility at a lower air speed than did the more accurate airfoil.
Date: February 1, 1938
Creator: Robinson, Russell G.
Item Type: Report

The Effect of Various Wing-Gun Installations on the Aerodynamic Characteristics of an Airplane Model Equipped with an NACA Low-Drag Wing, Special Report

Description: An investigation was made in the NACA 19-foot pressure wind tunnel to determine the effect of various win-gun installation on the aerodynamic characteristics of a model with an NACA low-drag wing. Measurements were made of lift and drag over an angle-of-attack range and for several values of dynamic pressure on a four-tenths scale model of a high-speed airplane equipped with the low-drag wing and with various wing-gun installations. Two installations were tested: one in which the blast tube and part of the gun barrel protrude ahead of the wing and another in which the guns is mounted wholly within the wing. Two types of openings for the latter installation were tested. For each installation three simulated guns were mounted in each wing. The results are given in the form of nondimensional coefficients. The installations tested appear to have little effect on the maximum-lift coefficient of the model. However, the drag coefficient shows a definite change. The least adverse effect was obtained with the completely internal mounting and small nose entrance. The results indicate that a properly designed wing-gun installation will have very little adverse effect on the aerodynamic characteristics of the low-drag wing.
Date: July 1, 1941
Creator: Muse, Thomas C.
Item Type: Report

The Effects of Aerodynamic Heating on Ice Formations on Airplane Propellers

Description: An investigation has been made of the effect of aerodynamic heating on propeller-blade temperatures. The blade temperature rise resulting from aerodynamic heating was measured and the relation between the resulting blade temperatures and the outer limit of the iced-over region was examined. It was found that the outermost station at which ice formed on a propeller blade was determined by the blade temperature rise resulting from the aerodynamic heating at that point.
Date: August 1, 1940
Creator: Rodert, Lewis A.
Item Type: Report

Effects of Direction of Propeller Rotation on the Longitudinal Stability of the 1/10-Scale Model of the North American XB-28 Airplane with Flaps Neutral, Special Report

Description: The effects of direction of propeller rotation on factors affecting the longitudinal stability of the XB-28 airplane were measured on a 1/10-scale model in the 7- by 10-foot tunnel of the Ames Aeronautical Laboratory. The main effect observed was that caused by regions of high downwash behind the nacelles (power off as well as power on with flaps neutral). The optimum direction of propeller rotation, both propellers rotating up toward the fuselage, shifted this region off the horizontal tail and thus removed its destabilizing effect. Rotating both propellers downward toward the fuselage moved it inboard on the tail and accentuated the effect, while rotating both propellers right hand had an intermediate result. Comparisons are made of the tail effects as measured by force tests with those predicted from the point-by-point downwash and velocity surveys in the region of the tail. These surveys in turn are compared with the results predicted from available theory.
Date: June 1, 1942
Creator: Delany, Noel K.
Item Type: Report