3-D Composite Velocity Solutions for Subsonic/transonic Flow Over Forebodies and Afterbodies


Book Description

A composite velocity procedure for the three-dimensional reduced Navier-Stokes equations is developed. In the spirit of matched asymptotic expansions, the velocity components are written as a combined multiplicative and additive composite of viscous like velocities (U, W) and pseudo-potential or inviscid velocities (phi sub x, phi sub y, phi sub z). The solution procedure is then consistent with both asymptotic inviscid flow and boundary layer theory. For transonic flow cases, the Enquist-Osher flux biasing scheme developed for the full potential equation is used. A quasi-conservation form of the governing equation is used in the shock region to capture the correct rotational behavior. This is combined with the standard nonconservation nonentropy generating form used in nonshock regions. The consistent strongly implicit procedure is coupled with plane relaxation to solve the discretized equations. The composites velocity procedure is coupled with plane relaxation to solve the discretized equations. The composits velocity procedure applied for the solution of three-dimensional afterbody problems.







Transonic Navier-Stokes Solutions of Three-Dimensional Afterbody Flows


Book Description

The performance of a three-dimensional Navier-Stokes solution technique in predicting the transonic flow past a nonaxisymmetric nozzle was investigated. The investigation was conducted at free-stream Mach numbers ranging from 0.60 to 0.94 and an angle of attack of 0 degrees. The numerical solution procedure employs the three-dimensional, unsteady, Reynolds-averaged Navier-Stokes equations written in strong conservation form, a thin layer assumption, and the Baldwin-Lomax turbulence model. The equations are solved by using the finite-volume principle in conjunction with an approximately factored upwind-biased numerical algorithm. In the numerical procedure, the jet exhaust is represented by a solid sting. Wind-tunnel data with the jet exhaust simulated by high pressure air were also obtained to compare with the numerical calculations. Compton, William B., III and Thomas, James L. and Abeyounis, William K. and Mason, Mary L. Langley Research Center...




NASA Technical Paper


Book Description







Cities and Their Vital Systems


Book Description

Cities and Their Vital Systems asks basic questions about the longevity, utility, and nature of urban infrastructures; analyzes how they grow, interact, and change; and asks how, when, and at what cost they should be replaced. Among the topics discussed are problems arising from increasing air travel and airport congestion; the adequacy of water supplies and waste treatment; the impact of new technologies on construction; urban real estate values; and the field of "telematics," the combination of computers and telecommunications that makes money machines and national newspapers possible.