UNT Libraries Government Documents Department - Browse


An approximate spin design criterion for monoplanes, 1 May 1939

Description: An approximate empirical criterion, based on the projected side area and the mass distribution of the airplane, was formulated. The British results were analyzed and applied to American designs. A simpler design criterion, based solely on the type and the dimensions of the tail, was developed; it is useful in a rapid estimation of whether a new design is likely to comply with the minimum requirements for safety in spinning.
Date: January 1, 1976
Creator: Seidman, O. & Donlan, C. J.

Liquid-in-Glass Thermometry

Description: Report containing information of general interest to manufacturers and users of liquid-in-glass thermometers. This report supersedes Monograph 90. Instructions explaining how to submit a thermometer to the National Bureau of Standards for calibration are provided, and the techniques and equipment, such as stirred liquid comparison baths, used in the calibration procedures are described. A discussion of important principles of acceptable thermometer design and factors affecting their use is included. Listed are tables of tolerances reflecting good manufacturing practices and reasonably attainable accuracies expected with liquid-in-glass thermometers. The calculation of corrections for the temperature of the emergent stem is given in detail for various types of thermometers and conditions of use.
Date: January 1976
Creator: Wise, Jacquelyn A.

Methods of analyzing wind-tunnel data for dynamic flight conditions

Description: The effects of power on the stability and the control characteristics of an airplane are discussed and methods of analysis are given for evaluating certain dynamic characteristics of the airplane that are not directly discernible from wind tunnel tests alone. Data are presented to show how the characteristics of a model tested in a wind tunnel are affected by power. The response of an airplane to a rolling and a yawing disturbance is discussed, particularly in regard to changes in wing dihedral and fin area. Solutions of the lateral equations of motion are given in a form suitable for direct computations. An approximate formula is developed that permits the rapid estimation of the accelerations produced during pull-up maneuvers involving abrupt elevator deflections.
Date: January 1, 1976
Creator: Donlan, C. J. & Recant, I. G.

Multicomponent Isotopic Separation and Recirculation Analysis

Description: A digital computer program for design of multi-component distillation columns has been developed based on an exact method of solution of the governing equations. Although this computer program was developed for enrichment of the spent fuels from presently conceived Tokamak-type fusion power reactors by cryogenic distillation, the program can be used for the design of any multi-component distillation column, provided, of course, the necessary thermodynamic and phase equilibrium data are available. To prove the versatility of the computer program, parametric investigations to study the effect of design and operating variables on the composition of the product streams was carried out for the case of separating hydrogen isotopes. The computer program is very efficient; hence, a number of parametric investigations can be carried out with limited resources. The program does, however, require a fairly large computer storage space (approximately 250 K bytes).
Date: January 1976
Creator: Misra, B. & Maroni, V. A.

Spin tests of a low-wing monoplane to investigate scale effect in the model test range, May 1941

Description: Concurrent tests were performed on a 1/16 and a 1/20 scale model (wing spans of 2.64 and 2.11 ft. respectively) of a modern low wing monoplane in the NACA 15 foot free-spinning wind tunnel. Results are presented in the form of charts that afford a direct comparison between the spins of the two models for a number of different conditions. Qualitatively, the same characteristic effects of control disposition, mass distribution, and dimensional modifications were indicated by both models. Quantitatively, the number of turns for recover and the steady spin parameters, with the exception of the inclination of the wing to the horizontal, were usually in good agreement.
Date: January 1, 1976
Creator: Donlan, C. J.

A Unified and Mechanistic Approach to Creep-Fatigue Damage

Description: A new creep-fatigue equation is proposed that takes into account both plastic strain and strain rate. The coefficients and exponents in the damage-rate equation are interpreted by means of the various damage mechanisms of the material. The damage-rate equation has been integrated to analyze various phenomena such as the effects of plastic strain rate on monotonic tensile or creep rupture time, rising mean strain on the low-cycle fatigue behavior at elevated temperature, tensile and compressive hold times on the low-cycle fatigue life at elevated temperature, and cyclic creep. The proposed approach has been successfully applied to elevated-temperature data generated at Argonne National Laboratory and elsewhere for Type 304 austenitic stainless steel under various monotonic and cyclic-loading conditions.
Date: January 1976
Creator: Majumdar, S. & Maiya, P. S.