Radiator Design and Installation (open access)

Radiator Design and Installation

"The fundamental principles of fluid flow, pressure losses, and heat transfer have been presented and analyzed for the case of a smooth tube with fully developed turbulent flow. These equations apply to tubes with large length-diameter ratios where the flow is at a high Reynolds Number. The error introduced by using these equations increases as the magnitude of the tube length and the air-flow Reynolds Number approaches the values encountered in modern radiator designs" (p. 1).
Date: May 1939
Creator: Brevoort, M. J. & Leifer, M.
System: The UNT Digital Library
Experiments on the Recovery of Waste Heat in Cooling Ducts, Special Report (open access)

Experiments on the Recovery of Waste Heat in Cooling Ducts, Special Report

Tests have been conducted in the N.A.C.A. full-scale wind tunnel to investigate the partial recovery of the heat energy which is apparently wasted in the cooling of aircraft engines. The results indicate that if the radiator is located in an expanded duct, a part of the energy lost in cooling is recovered; however, the energy recovery is not of practical importance up to airplane speeds of 400 miles per hour. Throttling of the duct flow occurs with heated radiators and must be considered in designing the duct outlets from data obtained with cold radiators in the ducts.
Date: May 1939
Creator: Silverstein, Abe
System: The UNT Digital Library
Comparison of Three Exit-Area Control Devices on an N.A.C.A. Cowling, Special Report (open access)

Comparison of Three Exit-Area Control Devices on an N.A.C.A. Cowling, Special Report

"Adjustable cowling flaps, an adjustable-length cowling skirt, and a bottom opening with adjustable flap were tested as means of controlling the rate of cooling-air flow through an air-cooled radial-engine cowling. The devices were tested in the NACA 20-foot tunnel on a model wing-nacelle-propeller combination, through an airspeed range of 20 to 80 miles per hour, and with the propeller blade angle set 23 degrees at 0.75 of the tip radius. The resistance of the engine to air flow through the cowling was simulated by a perforated plate" (p. 1).
Date: May 1940
Creator: McHugh, James G.
System: The UNT Digital Library
Restraint Provided a Flat Rectangular Plate by a Sturdy Stiffener Along an Edge of the Plate, Special Report (open access)

Restraint Provided a Flat Rectangular Plate by a Sturdy Stiffener Along an Edge of the Plate, Special Report

A sturdy stiffener is defined as a stiffener of such proportions that it does not suffer cross-sectional distortion when moments are applied to some part of the cross section. When such a stiffener is attached to one edge of a plate, it will resist rotation of that edge of the plate by means of its torsional properties. A formula is given for the restraint coefficient provided the plate by such a stiffener. This coefficient is required for the calculation of the critical compressive stress of the plate.
Date: May 1941
Creator: Lundquist, Eugene E. & Stowell, Elbridge Z.
System: The UNT Digital Library
Comparison of Intercooler Characteristics (open access)

Comparison of Intercooler Characteristics

"A method is presented of comparing the performance, weight, and general dimensional characteristics of inter-coolers. The performance and dimensional characteristics covered in the comparisons are cooling effectiveness, pressure drops and weight flows of the charge and cooling air, power losses, volume, frontal area, and width. A method of presenting intercooler data is described in which two types of charts are plotted; (1) A performance chart setting forth all the important characteristics of a given intercooler and (2) a replot of these characteristics for a number of intercoolers intended to assist in making a selection to satisfy a given set of installation conditions" (p. 1).
Date: May 1941
Creator: Reuter, J. George & Valerino, Michael F.
System: The UNT Digital Library
Performance Characteristics of an Aircraft Engine with Exhaust Turbine Supercharger, Special Report (open access)

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

"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" (p. 1).
Date: May 1941
Creator: Lester, E. M. & Paulson, W. A.
System: The UNT Digital Library
Definition of Method of Measurement of Supporting and Control Surface Areas (open access)

Definition of Method of Measurement of Supporting and Control Surface Areas

Definitions of methods of measurements of supporting and control surface areas are presented. Methods for measuring the supporting surface, i.e., the wing area, and the control surfaces, i.e., the horizontal tail area, the vertical tail area, and the trailing control surface areas are defined. Illustrations of each of the areas are included.
Date: May 1931
Creator: unknown
System: The UNT Digital Library
A Brief Study of the Speed Reduction of Overtaking Airplanes by Means of Air Brakes (open access)

A Brief Study of the Speed Reduction of Overtaking Airplanes by Means of Air Brakes

"As an aid to airplane designers interested in providing pursuit airplanes with decelerating devices intended to increase the firing time when overtaking another airplane, formulas are given relating the pertinent distances and speeds in horizontal flight to the drag increase required. Charts are given for a representative parasite-drag coefficient from which the drag increase, the time gained, and the closing distance may be found. The charts are made up for three values of the ratio of the final speed of the pursuing airplane to the speed of the pursued airplane and for several values of the ratio of the speed of the pursued airplane to the initial speed of the pursuing airplane" (p. 1).
Date: May 1942
Creator: Pearson, H. A. & Anderson, R. F.
System: The UNT Digital Library
Critical Compressive Stress for Flat Rectangular Plates Supported Along all Edges and Elastically Restrained Against Rotation Along the Unloaded Edges (open access)

Critical Compressive Stress for Flat Rectangular Plates Supported Along all Edges and Elastically Restrained Against Rotation Along the Unloaded Edges

A chart is presented for the values of the coefficient in the formula for the critical compressive stress at which buckling may be expected to occur in flat rectangular plates supported along all edges and, in addition, elastically restrained against rotation along the unloaded edges. The mathematical derivations of the formulas required in the construction of the chart are given.
Date: May 1941
Creator: Lundquist, Eugene E. & Stowell, Elbridge Z.
System: The UNT Digital Library
A Study of Transparent Plastics for use on Aircraft, Special Report (open access)

A Study of Transparent Plastics for use on Aircraft, Special Report

"Various transparent organic plastics, including both commercially available and experimental materials, have been examined to determine their suitability for use as flexible windshields on aircraft, The properties which have been studied include light transmission, haziness, distortion, resistance to weathering, scratch and indentation hardness, impact strength, dimensional stability, resistance to water and various cleaning fluids, bursting strength at normal and low temperatures, and flammability" (p. 1).
Date: May 12, 1937
Creator: Axilrod, Benjamin M. & Kline, Gordon M.
System: The UNT Digital Library