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 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

Transonic similarity solution for aligned field MHD nozzle flow

The transonic flow near the throat of a converging-diverging nozzle of a gas with infinite electrical conductivity is considered. The magnetic field B is everywhere aligned with the velocity q so that the equations describing the flow are reducible to those of ordinary gasdynamics. Thus, it is possible to utilize the transonic similarity solution of Tomotika and Tamada [3] to study aligned field magnetohydrodynamic flow near a nozzle throat. Only transonic flows are considered, and the structures of sub- and supersonic flows with speeds greater and less than the Alfvén speed are investigated.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42703/1/10665_2005_Article_BF01535358.pd