Metal organic chenlical vapor deposition （AIOCVD） growth systems arc one of the. main types of equipment used for growing single crystal materials, such as GaN. To obtain fihn epitaxial materials with uniform perfor...Metal organic chenlical vapor deposition （AIOCVD） growth systems arc one of the. main types of equipment used for growing single crystal materials, such as GaN. To obtain fihn epitaxial materials with uniform performanee, the flow field and ternperature field in a GaN-MOCVD reactor are investigated by modeling and simulating. To make the simulation results more consistent with the actual situation, the gases in the reactor are considered to be compressible, making it possible to investigate the distributions of gas density and pressure in the reactor. The computational fluid dynamics method is used to stud,v the effects of inlet gas flow velocity, pressure in the reactor, rotational speed of graphite susceptor, and gases used in the growth, which has great guiding~ significance for the growth of GaN fihn materials.展开更多
A novel model for dynamic temperature distribution in heavy oil reservoirs is derived from the principle of energy conservation.A difference equation of the model is firstly separated into radial and axial difference ...A novel model for dynamic temperature distribution in heavy oil reservoirs is derived from the principle of energy conservation.A difference equation of the model is firstly separated into radial and axial difference equations and then integrated.Taking into account the coupling of temperature and pressure in the reservoir and wellbore,models for calculating distributions of the reservoir temperature,reservoir pressure,and water saturation are also developed.The steam injected into the wellbore has a more significant effect on reservoir pressure than on reservoir temperature.Calculation results indicate that the reservoir temperature and pressure decrease exponentially with increasing distance from the horizontal wellbore.The radial variation range of the pressure field induced by steam is twice as wide as that of the temperature field,and both variation ranges decrease from the wellbore heel to the toe.Variation of water saturation induced by steam is similar to the temperature and pressure fields.The radial variation ranges of the reservoir temperature and pressure increase with steam injection time,but rate of increase diminishes gradually.展开更多
基金Supported by the National Key R&D Program of China under Grant No 2016YFB0400104
文摘Metal organic chenlical vapor deposition （AIOCVD） growth systems arc one of the. main types of equipment used for growing single crystal materials, such as GaN. To obtain fihn epitaxial materials with uniform performanee, the flow field and ternperature field in a GaN-MOCVD reactor are investigated by modeling and simulating. To make the simulation results more consistent with the actual situation, the gases in the reactor are considered to be compressible, making it possible to investigate the distributions of gas density and pressure in the reactor. The computational fluid dynamics method is used to stud,v the effects of inlet gas flow velocity, pressure in the reactor, rotational speed of graphite susceptor, and gases used in the growth, which has great guiding~ significance for the growth of GaN fihn materials.
文摘A novel model for dynamic temperature distribution in heavy oil reservoirs is derived from the principle of energy conservation.A difference equation of the model is firstly separated into radial and axial difference equations and then integrated.Taking into account the coupling of temperature and pressure in the reservoir and wellbore,models for calculating distributions of the reservoir temperature,reservoir pressure,and water saturation are also developed.The steam injected into the wellbore has a more significant effect on reservoir pressure than on reservoir temperature.Calculation results indicate that the reservoir temperature and pressure decrease exponentially with increasing distance from the horizontal wellbore.The radial variation range of the pressure field induced by steam is twice as wide as that of the temperature field,and both variation ranges decrease from the wellbore heel to the toe.Variation of water saturation induced by steam is similar to the temperature and pressure fields.The radial variation ranges of the reservoir temperature and pressure increase with steam injection time,but rate of increase diminishes gradually.
