Yasuhiro Wada

Numerical Simulation of Re-Entry Flow Around the Space Shuttle with Finite-Rate Chemistry

Hypersonic flow around the Space Shuttle is computed for a series of re-entry flight conditions by incorporating a one-temperature model that takes into account 7-species finite-rate chemistry. An implicit higher-order upwind scheme based on a generalized Roes approximate Riemann is used. The aerodynamic characteristics and heating rates are compared with the STS-2 flight data, and good agreement is obtained. These results quantitatively confirm the measured forward shift of the center of pressure and reduction of heating rates caused by real gas effects.

A Fully Implicit High-Resolution Scheme for Chemically Reacting Compressible Flows

The eigenvalues and eigenvectors are analytically derived for general real gas dynamic equations in three-dimensional generalized curvilinear coordinates. In our diagonalizing formulation, the total mass conservation equation is taken into account, and arbitrary nonequilibrium effects, such as chemical reactions or vibrational nonequilibrium, can be treated in the same fashion. Making use of this diagonalization, we construct a fully implicit and high resolution scheme for chemically reacting real gases. Numerical results of two-dimensional shock-induced combustion problem show the efficiency and high resolution of our scheme.

Numerical Analysis On Gain Of C6H6-O2-N2 Type GDL

The two-dimensional vibrational non-equilibrium flow field and the nozzle shape effects on CO2 GDL (Gasdynamic Laser) performance are numerically analyzed by a point implicit scheme. It is shown that the Shock Free Minimum Length nozzle (SFML-nozzle) is superior to other nozzles in the viewpoint of GDL characteristics such as the small-signal gain and the maximum power available. Furthermore, the effects of combustion by-products such as O2,CO on the small-signal gain are investigated. It is concluded that such by-products have a negative effect on GDL gain characteristics. The effects of H20 concentration on the small-signal gain are also investigated considering H2O vibrational relaxation. These numerical analyses are performed for the predictions of CO2 GDL.

Numerical investigation of separated flow around a bent-nose biconic

Abstract The purpose of this article is to investigate the separated flow around the bent-nose biconic, in which the second-order TVD (total variation diminishing) method is applied and the numerical flux is a Harten-Yee type. The governing equation is a thin layer Navier-Stokes equation. The boundary condition on the wall is the adiabatic wall. The whole flow field is laminar. The numerical conditions are as follows: Mach number 7.0, Reynolds number 8.38·105. The surface pressure distribution at the leeward side is a little higher in the vicinity of the symmetrical plane. This seems to be caused by the development of the vortex at the leeward side due to the separated flow. The location of a separation line and the size are in very good agreement with the experiment. Also the secondary separation is captured very clearly. The characteristics of the separated flow around the bent-nose biconic are clarified.