Sonic boom research

The results of sonic boom research studies are presented. The purpose of the studies was as follows: (1) to minimize the sonic boom of supersonic transport aircraft, (2) to predict the distortion of the sonic boom signature by atmospheric turbulence, and (3) to predict the amplifications that occurs at a caustic, known as a superboom. The aircraft and meteorological parameters which can be used to predict sonic boom intensity are identified. A bibliography of publications on sonic booms is included

Improvements to embedded shock wave calculations for transonic flow-applications to wave drag and pressure rise predictions

The numerical solution of a single, mixed, nonlinear equation with prescribed boundary data is discussed. A second order numerical procedure for solving the nonlinear equation and a shock fitting scheme was developed to treat the discontinuities that appear in the solution

Transonic flow studies

Major emphasis was on the design of shock free airfoils with applications to general aviation. Unsteady flow, transonic flow, and shock wave formation were examined

Inviscid transonic flow computations with shock fitting

First-and second-order numerical procedures are presented for calculating two-dimensional transonic flows that treat shock waves as discontinuities. Their application to a simple but nontrivial problem for which there are limited theoretical results is discussed

Finite area method for nonlinear supersonic conical flows

A fully conservative numerical method for the computation of steady inviscid supersonic flow about general conical bodies at incidence is described. The procedure utilizes the potential approximation and implements a body conforming mesh generator. The conical potential is assumed to have its best linear variation inside each mesh cell; a secondary interlocking cell system is used to establish the flux balance required to conserve mass. In the supersonic regions the scheme is symmetrized by adding artificial viscosity in conservation form. The algorithm is nearly an order of a magnitude faster than present Euler methods and predicts known results accurately and qualitative features such as nodal point lift off correctly. Results are compared with those of other investigators

A corporate supersonic transport

This talk address the market and technology for a corporate supersonic transport. It describes a candidate configuration. There seems to be a sufficient market for such an aircraft, even if restricted to supersonic operation over water. The candidate configuration's sonic boom overpressure may be small enough to allow overland operation as well

A new method for designing shock-free transonic configurations

A method for the design of shock free supercritical airfoils, wings, and three dimensional configurations is described. Results illustrating the procedure in two and three dimensions are given. They include modifications to part of the upper surface of an NACA 64A410 airfoil that will maintain shock free flow over a range of Mach numbers for a fixed lift coefficient, and the modifications required on part of the upper surface of a swept wing with an NACA 64A410 root section to achieve shock free flow. While the results are given for inviscid flow, the same procedures can be employed iteratively with a boundary layer calculation in order to achieve shock free viscous designs. With a shock free pressure field the boundary layer calculation will be reliable and not complicated by the difficulties of shock wave boundary layer interaction

Ersatzschaltbild für die Rückwirkung der Wirbelströme in einem endlich langen Hohlzylinder auf den Stromkreis eines koaxialen zylindrischen Leiters

Es werden alle Größen für das Ersatzschaltbild angegeben, das die Rückwirkung der Wirbelströme in einem endlich langen Hohlzylinder, der koaxial einen zylindrischen Leiter umgibt, auf dessen Stromkreis beschreibt. Weiterhin werden Näherungswerte für die Kenngrößen des Ersatzschaltbildes angegeben für den Fall, daß das Radienverhältnis des Hohlzylinders kleiner als 2 ist.There are given all circuit elements for the equivalent circuit diagram that describes the back effect of eddy currents within a hollow cylinder of finite length surrounding a coaxial cylindric conductor, on the circuit of this conductor. Furthermore for the case that the ratio of the outer diameter to the inner diameter of the hollow cylinder does not exceed the value of 2 there are given approximate values for the circuit elements of the equivalent circuit diagram