Computation of Steady and Unsteady Quasi-One-Dimensional Viscous/Inviscid Interacting Internal Flows at Subsonic, Transonic, and Supersonic Mach Numbers

Download or read book Computation of Steady and Unsteady Quasi-One-Dimensional Viscous/Inviscid Interacting Internal Flows at Subsonic, Transonic, and Supersonic Mach Numbers written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-17 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computations of viscous-inviscid interacting internal flowfields are presented for steady and unsteady quasi-one-dimensional (Q1D) test cases. The unsteady Q1D Euler equations are coupled with integral boundary-layer equations for unsteady, two-dimensional (planar or axisymmetric), turbulent flow over impermeable, adiabatic walls. The coupling methodology differs from that used in most techniques reported previously in that the above mentioned equation sets are written as a complete system and solved simultaneously; that is, the coupling is carried out directly through the equations as opposed to coupling the solutions of the different equation sets. Solutions to the coupled system of equations are obtained using both explicit and implicit numerical schemes for steady subsonic, steady transonic, and both steady and unsteady supersonic internal flowfields. Computed solutions are compared with measurements as well as Navier-Stokes and inverse boundary-layer methods. An analysis of the eigenvalues of the coefficient matrix associated with the quasi-linear form of the coupled system of equations indicates the presence of complex eigenvalues for certain flow conditions. It is concluded that although reasonable solutions can be obtained numerically, these complex eigenvalues contribute to the overall difficulty in obtaining numerical solutions to the coupled system of equations. Swafford, Timothy W. and Huddleston, David H. and Busby, Judy A. and Chesser, B. Lawrence Unspecified Center COMPUTATIONAL FLUID DYNAMICS; FLOW DISTRIBUTION; MACH NUMBER; NAVIER-STOKES EQUATION; NUMERICAL ANALYSIS; SUBSONIC FLOW; SUPERSONIC FLOW; TRANSONIC FLOW; UNSTEADY FLOW; VISCOUS FLOW; ADIABATIC CONDITIONS; AXISYMMETRIC FLOW; BOUNDARY LAYERS; EULER EQUATIONS OF MOTION; INTEGRAL EQUATIONS; INVISCID FLOW; TURBULENT FLOW; WALL TEMPERATURE...