In this presentation, first, the high-order upwind finite difference scheme is considered for the gas-particle multi-phase shock containing flows. We used an alternative weighted essentially non oscillation scheme (AWENO) which is the numerical flux formulation of a kind of weighted compact nonlinear scheme and the use of a positive preserving limiter proposed recently which can be used with numerical flux formulation. AN AWENO scheme with a positivity preserving limiter for the density of solid particles are implemented to the gas-particle multiphase flow solver. With an AWENO scheme, we conducted 2-dimensional numerical test problem. As a result, higher resolution is obtained without blowing up of the computation by using an AWENO scheme.

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Interaction of unsteady shock wave and Karman's vortex is experimentally investigated in a wind tunnel. Karman's vortex is generated behind a cylindrical bar and the Reynolds number based on the mean velocity and the cylinder diameter is set to 849. A spherical shock wave is emanated from an open end of a shock tube installed far downstream of the bar and propagates in the upstream direction. The shock wave is successfully captured by a high-speed camera and instantaneous fluid velocity interacted with the shock wave is calculated by means of particle image velocimetry (PIV). The visualized velocity and vorticity distributions show that both the streamwise velocity fluctuation and vorticity of the Karman's vortex are decreased by the shock wave.

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The applied research on the next generation propulsion engine utilizing high energy of the detonation has been performed. However, the detonation is high speed combustion phenomena, and then it is very difficult to reveal the detail structure. In this study, the spin detonation has been reproduced by three dimensional numerical analysis with transport phenomena, and the viscous effect has been evaluated by the density distribution of chemical species and propagation behavior. At the same time, discussion about the fluctuation behavior of the propagation velocity and the maximum pressure on the presence or absence of transport effects also have been done. The numerical calculation has been approximated by finite difference method using the semi-implicit MacCormack TVD scheme.

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We conduct a detailed evaluation of a WCNS with Roe's FDS or a simple low-dissipation advection scheme for fundamental flow simulations with a strong shock wave. A shock-boundary layer interaction, where the boundary layer undergoes transition to turbulence, and the interaction with a strong shock wave and a strong vortex have been performed. The numerical results are compared with experimental and previous DNS/WENO numerical results.

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In the present study, the effect of aspect ratio (length-to-depth ratio) on the pressure oscillation induced by a rectangular cavity over which the gas flows at a supersonic speed is investigated experimentally. The temporal variations in pressure are measured with the semiconductor-type pressure transducer on the wall changing the aspect ratio of the cavity and the power spectral densities are calculated for each aspect ratio. As a result, it is found that the transition between the transverse and longitudinal oscillations occurs between the aspect ratios 〜1 and 〜2.

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An underexpanded jet is one of supersonic jets. The jet becomes underexpanded when the pressure ratio exceeds the critical value across an axisymmetric convergent nozzle discharging it. The jet is not uniform because of the presence of the expansion wave, the compression wave and the shock wave formed in it. Moreover, when a flat plate is placed perpendicularly to the jet, the strong wave called 'plate shock' appears in the flow field near the plate. The jet which exhausts from a nozzle to the atmosphere is often used for industrial applications such as an assist gas of the laser cutting, a cooling jet in the glass tempering process, etc. In this study, a structure of impinging jet on a flat plate was experimentally examined. The flow field was visualized using Schlieren and shadowgraph methods. In addition, under the same conditions, a numerical study was carried out using TVD scheme.

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The behavior of the laser induced plasma was simulated numerically. The simulation code was verified by the calculation of the point explosion. The pressure distribution agrees well with Taylor-Sedov self-similar solution. Based on this verification, by using the laser power distribution model, the behavior of the laser induced plasma was simulated. After several hundred micro second, the plasma deformed as like injection jet against toward the laser irradiation direction.

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Navier-Stokes simulations have been conducted to systematically investigate the aerodynamic characteristics of wings with 45 degree swept back angle, and wing sections of different maximum thickness position of biconvex airfoil. The Mach numbers of the flows are from 0.8 to 2.8. The half span planforms of wings is parallelogram whose aspect ratio is 2. The simulation and investigation has revealed new knowledge on the relation between leading/trailing edge radius and aerodynamic characteristics of a wing in a supersonic flow.

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