Based on C-J (Chapman-Jouguet) theory different reference states of gaseous detonation products and unreacted explosives in detonation problem are considered. According to these reference states, specific Mie-Grüneisen EOS (equation of states) is selected. As chemical reaction process is neglected, a zero-thickness section of guided shock wave exists as an interface in front of the detonation wave. In numerical simulation, evolution of detonation wave includes two parts:Propagation of wave section, as well as interaction with unreacted medium. In the propagation process, speed is defined as the constant detonation speed, and detonation products forms instantly. In the interaction process, Mie-Grüneisen mixture model is employed to simulate continuous impact of detonation wave. With Mie-Grüneisen EOS, as well as the Mie-Grüneisen mixture model, motion of detonation wave is simulated well. Comparing with related theoretical data and numerical results good performance was found.

A revised robust HLLC(Harten-Lax-Van Leer-Contact) solver for multi-component Mie-Grüneisen mixture model is established. In Mie-Grüneisen mixture model, flux can be divided into conservative part and non-conservative part. Original HLLC scheme can well adapt to conservative part. As the original HLLC solver is directly extended to non-conservative part, oscillation is hard to be controlled. In original scheme, moving speed of discontinuous section refers to velocity at left or right side of the gird. It is replaced by average velocity within the grid. After the revision, the HLLC scheme is deduced again and extended to 2D problem. Numerical tests show that Mie-Grüneisen mixture model is robust and accurate with the help of modified HLLC solver.

Numerical study based on a wake oscillator model is conducted to determine response performance of vortex-induced vibration (VIV) on a rigid cylinder. A coupled model of structural oscillator of a rigid cylinder and wake oscillator is established, and then the model is discretized and solved based on a standard central finite difference method of the second order. VIV response characteristics including dimensionless displacement, dimensionless lift, and frequency ratio and lock-in region varied with mass ratios and damping ratios are compared. It can be found that the numerical method simulates response performances of vortex-induced vibration on a rigid cylinder very well. As dimensionless mass ratio increases, onset of lock-in region occurs later, lock-out point occurs earlier, and so the lock-in region becomes smaller.

Flows past a pair of rotating circular cylinders in tandem arrangement at Re=100 are studied numerically.Multi-block lattice Boltzmann method(LBM) is used.Basic features of vortex shedding and forces acting on rotating circular cylinders are studied with comprehensive analysis of impact of cylindrical center spacing ratio S/D and rotational speed α.There exists a critical rotating speed at S/D=1.2,exceeding which the former cylinder produces a negative Magnus lift;As S/D=2,flow field emerges a second unstable mode similar to a single rotating cylinder;At relative large spacings(S/D=4、6),vortex sheds between cylinders.Wake flows of the later cylinder present a variety of forms of 2S、2S^*、2P、P+S and so on.

For multi-component fluid field under Mie-GrÜneisen equation of state,we consider some complex coefficients in Euler equations as conserved variables,and add new equations to simplify structure of original equation.In addition,mass fraction is introduced for different medium in field and flux is treated approximately.With modified Euler equation system and a MUSCL-TVD scheme we simulate interaction of different medium characterized by Mie-Graneisen equation of state.It shows that the approach makes the equations conserved and treats sharp interfaces with different medium well.

We study an inverse problem of reconstructing a 3D object in an ocean waveguide from far-field measurements of scattered field.An indicator sampling method for fast imaging of scattering object is presented.The method does not depend on any acoustic and geometric properties of the scattering object.It is valid for obtaining good imaging of location and shape of the scattering object,even as far-field data are measured in a limited aperture and corrupted by noise.Generally,multiple scattering between object and waveguide boundaries has positive influence on reconstruction of the scattering object.

Taking vorticity equation as a controlling equation, we simulate three vortexes developing progress with initial condition of Gaussian probability vorticity distribution. The wavelet expression of vorticity contains scaling coefficient term and wavelet coefficient tenn. The latter can be divided into a significant wavelet coefficient term and a trivial wavelet coefficient term reference to a given critical value. The critical value contains practical flow information. The vorticity is reconstructed only with scaling coefficients and significant wavelet coefficients. It saves computing time and capture most part of entrophy. Numerical results show that scaling coefficients together with significant wavelet coefficients is less than 10% of total wavelet coefficients, but they contains more than 99% of total enstrophy.