Bodies of revolution having minimum drag at high supersonic airspeeds (open access)

Bodies of revolution having minimum drag at high supersonic airspeeds

Approximate shapes of nonlifting bodies having minimum pressure foredrag at high supersonic airspeeds are calculated. With the aid of Newton's law of resistance, the investigation is carried out for various combinations of the conditions of given body length, base diameter, surface area, and volume. In general, it is found that when body length is fixed, the body has a blunt nose; whereas, when the length is not fixed, the body has a sharp nose. The additional effect of curvature of the flow over the surface is investigated to determine its influence on the shapes for minimum drag. The effect is to increase the bluntness of the shapes in the region of the nose and the curvature in the region downstream of the nose. These shape modifications have, according to calculation, only a slight tendency to reduce drag. Several bodies of revolution of fineness ratios 3 and 5, including the calculated shapes of minimum drag for given length and base diameter and for given base diameter and surface area, were tested at Mach numbers from 2.73 to 6.28. A comparison of theoretical and experimental foredrag coefficients indicates that the calculated minimum-drag bodies are reasonable approximations to the correct shape.
Date: December 14, 1955
Creator: Eggers, A. J., Jr.; Resnikoff, Meyer M. & Dennis, David H.
System: The UNT Digital Library
Solutions of the Reactor Kinetics Equations for Time-Dependent Reactivities (open access)

Solutions of the Reactor Kinetics Equations for Time-Dependent Reactivities

Abstract: The reactor kinetics equations are combined into a single integral equation whose kernel describes the time-dependent characteristics of the reactor including six delayed groups of neutrons. Numerical solutions of the integral equation are given for constant, linear, and ∫sin²kx dx reactivities. An approximate solution of the integral equation is obtained which provides a basis for the formulation and solution of the reactor system control problem using the methods of servomechanisms theory. The reactor frequency response function, a product of the approximate solution, is calculated and plot given.
Date: December 14, 1955
Creator: Ash, Milton S.
System: The UNT Digital Library
THE USE OF THERMISTORS IN CRYOSCOPIC MEASUREMENTS (open access)

THE USE OF THERMISTORS IN CRYOSCOPIC MEASUREMENTS

None
Date: December 14, 1955
Creator: McMullen, R.K. & Corbett, J.D.
System: The UNT Digital Library