A finite difference lattice Boltzmann method of second-order accuracy in time is developed based on non-oscillatory scheme with no-free-parameter dissipation （NND） difference scheme in this paper. The NND lattice Bo...A finite difference lattice Boltzmann method of second-order accuracy in time is developed based on non-oscillatory scheme with no-free-parameter dissipation （NND） difference scheme in this paper. The NND lattice Boltzmann method is used to simulate high-speed flows by constructing a new equilibrium distribution function of the lattice Boltzmann method. Compared with a variation of lattice Boltzmann method developed by Qu, et al., the present method can capture shock waves and handle oscillations of high velocity flows accurately in larger time steps and in shorter computing time. Numerical results indicate the correctness and capability of simulating shock wave interactions of the NND lattice Boltzmann method.展开更多
This article experimentally investigated the pressure and cavitation characteristics of high velocity flow over a surface irregularity with and without aeration in a non-circulating water tunnel system. The surface ir...This article experimentally investigated the pressure and cavitation characteristics of high velocity flow over a surface irregularity with and without aeration in a non-circulating water tunnel system. The surface irregularity is a cylindrical protrusion made of stainless steel of 6 mm diameter and 2 mm height. Pressures with and without aeration were measured with MPX400D pressure transducers and real-timely acquired by a SINOCERA YE6263 data acquisition system. Variations in flow regimes with and without aeration were observed. Pressure profiles and their variations with air concentration upper and lower cylindrical protrusion on the invert and obvert walls were determined. Variations of cavitation number with air concentration lower cylindrical protrusion were analyzed. Also, cavitation numbers in the presence and absence of aeration were compared.展开更多
基金Project supported by the Aeronautics Science Foundation (Grant No.20061431)the Program for Changjiang Scholars and Innovative Research Team in University (Grant No.IRT0844)
文摘A finite difference lattice Boltzmann method of second-order accuracy in time is developed based on non-oscillatory scheme with no-free-parameter dissipation （NND） difference scheme in this paper. The NND lattice Boltzmann method is used to simulate high-speed flows by constructing a new equilibrium distribution function of the lattice Boltzmann method. Compared with a variation of lattice Boltzmann method developed by Qu, et al., the present method can capture shock waves and handle oscillations of high velocity flows accurately in larger time steps and in shorter computing time. Numerical results indicate the correctness and capability of simulating shock wave interactions of the NND lattice Boltzmann method.
基金the National Natural ScienceFoundation of China (Grant Nos: 50579067 and 50539070).
文摘This article experimentally investigated the pressure and cavitation characteristics of high velocity flow over a surface irregularity with and without aeration in a non-circulating water tunnel system. The surface irregularity is a cylindrical protrusion made of stainless steel of 6 mm diameter and 2 mm height. Pressures with and without aeration were measured with MPX400D pressure transducers and real-timely acquired by a SINOCERA YE6263 data acquisition system. Variations in flow regimes with and without aeration were observed. Pressure profiles and their variations with air concentration upper and lower cylindrical protrusion on the invert and obvert walls were determined. Variations of cavitation number with air concentration lower cylindrical protrusion were analyzed. Also, cavitation numbers in the presence and absence of aeration were compared.
