Azimuthal distributions of radial （transverse） momentum, mean radial momentum, and mean radial velocity of final-state particles are suggested for relativistic heavy ion collisions. Using the AMPT transport model wi...Azimuthal distributions of radial （transverse） momentum, mean radial momentum, and mean radial velocity of final-state particles are suggested for relativistic heavy ion collisions. Using the AMPT transport model with string melting, the distributions of Au＋Au collisions at 200 GeV are presented and studied. It is demonstrated that the distribution of total radial momentum is more sensitive to the anisotropic expansion, as the anisotropies of final-state particles and their associated transverse momentums are both counted in the measurement. The mean radial velocity distribution is compared with the radial flow velocity. The thermal motion contributes an isotropic constant to the mean radial velocity.展开更多
This paper presents comparative numerical studies to investigate the effects of blade sweep on inlet flow in axial compressor cascades. A series of swept and straight cascades was modeled in order to obtain a general ...This paper presents comparative numerical studies to investigate the effects of blade sweep on inlet flow in axial compressor cascades. A series of swept and straight cascades was modeled in order to obtain a general understanding of the inlet flow field that is induced by sweep.A computational fluid dynamics（CFD） package was used to simulate the cascades and obtain the required three-dimensional（3D） flow parameters. A circumferentially averaged method was introduced which provided the circumferential fluctuation（CF） terms in the momentum equation.A program for data reduction was conducted to obtain a circumferentially averaged flow field.The influences of the inlet flow fields of the cascades were studied and spanwise distributions of each term in the momentum equation were analyzed. The results indicate that blade sweep does affect inlet radial equilibrium. The characteristic of radial fluid transfer is changed and thus influencing the axial velocity distributions. The inlet flow field varies mainly due to the combined effect of the radial pressure gradient and the CF component. The axial velocity varies consistently with the incidence variation induced by the sweep, as observed in the previous literature. In addition, factors that might influence the radial equilibrium such as blade camber angles, solidity and the effect of the distance from the leading edge are also taken into consideration and comparatively analyzed.展开更多
基金Supported by National Natural Science Foundation of China (10835005)MOE of China (IRT0624, B08033)
文摘Azimuthal distributions of radial （transverse） momentum, mean radial momentum, and mean radial velocity of final-state particles are suggested for relativistic heavy ion collisions. Using the AMPT transport model with string melting, the distributions of Au＋Au collisions at 200 GeV are presented and studied. It is demonstrated that the distribution of total radial momentum is more sensitive to the anisotropic expansion, as the anisotropies of final-state particles and their associated transverse momentums are both counted in the measurement. The mean radial velocity distribution is compared with the radial flow velocity. The thermal motion contributes an isotropic constant to the mean radial velocity.
基金support of the National Natural Science Foundation of China(Grant Nos:51236001,51006005)
文摘This paper presents comparative numerical studies to investigate the effects of blade sweep on inlet flow in axial compressor cascades. A series of swept and straight cascades was modeled in order to obtain a general understanding of the inlet flow field that is induced by sweep.A computational fluid dynamics（CFD） package was used to simulate the cascades and obtain the required three-dimensional（3D） flow parameters. A circumferentially averaged method was introduced which provided the circumferential fluctuation（CF） terms in the momentum equation.A program for data reduction was conducted to obtain a circumferentially averaged flow field.The influences of the inlet flow fields of the cascades were studied and spanwise distributions of each term in the momentum equation were analyzed. The results indicate that blade sweep does affect inlet radial equilibrium. The characteristic of radial fluid transfer is changed and thus influencing the axial velocity distributions. The inlet flow field varies mainly due to the combined effect of the radial pressure gradient and the CF component. The axial velocity varies consistently with the incidence variation induced by the sweep, as observed in the previous literature. In addition, factors that might influence the radial equilibrium such as blade camber angles, solidity and the effect of the distance from the leading edge are also taken into consideration and comparatively analyzed.
