A kind of three-dimensional flow-path of the ram-rotor was designed in this paper according to the design method of the typical supersonic intake of aircraft and missiles,especially the design method of the compressio...A kind of three-dimensional flow-path of the ram-rotor was designed in this paper according to the design method of the typical supersonic intake of aircraft and missiles,especially the design method of the compression ramp,the throat and the subsonic diffuser.The design Mach number of the flow-path was based on the averaged relative Mach number,regardless of the change of incoming Mach number along radial direction of the flow-path.Then,the flowfield of the designed flow-path was simulated numerically with computational fluid dynamics software at design point.The purpose of simulation was to obtain the details of the flowfield,including the structure of the shock wave system,position of flow separation zone,and so on.The performance of the ram-rotor was also evaluated.The numerical results show the structure of the shock wave system in the flow-path is similar to that in the supersonic intake.To improve the overall performance of the ram-rotor,the reasonable compromise between the total pressure ratio and the isentropic adiabatic efficiency should be reached.The structure optimization of the flow-path and the configuration of the shock wave system have great influence on the performance of the ram-rotor.展开更多
重力储能系统(gravity energy storage system,GESS)在充电过程中可以从电网或新能源场站吸收电能。当新能源场站功率波动导致充电功率不足时,可选择两条能流路径应对充电功率波动,即调节质量块数量或直接从电网吸收能量,但如何合理选...重力储能系统(gravity energy storage system,GESS)在充电过程中可以从电网或新能源场站吸收电能。当新能源场站功率波动导致充电功率不足时,可选择两条能流路径应对充电功率波动,即调节质量块数量或直接从电网吸收能量,但如何合理选择上述路径是工程应用中的难题。为解决上述难题,提出了一种基于效益分析的重力储能系统能流路径选择方法,实现新能源站功率波动下的充电效益最优。首先,以斜坡式重力储能系统为例,对其储能过程中两条能量流动路径进行了详细分析;其次,以效益最优为目标建立了效益分析模型,并提出了上述能流路径下的功率缺额阈值计算方法;最后,以配置250 kW斜坡重力储能系统的800 kW光伏电站为例,在新能源波动条件下对比分析了采用不同能流路径时的储能系统充电成本及效益,对所提方法进行验证。结果表明,所提方法能够及时调整重力储能系统充电功率,有效解决新能源发电量不足问题,同时系统充电效益可提高44.95%。展开更多
基金Supported by National High-tech R&D Program(2007AA05Z255)
文摘A kind of three-dimensional flow-path of the ram-rotor was designed in this paper according to the design method of the typical supersonic intake of aircraft and missiles,especially the design method of the compression ramp,the throat and the subsonic diffuser.The design Mach number of the flow-path was based on the averaged relative Mach number,regardless of the change of incoming Mach number along radial direction of the flow-path.Then,the flowfield of the designed flow-path was simulated numerically with computational fluid dynamics software at design point.The purpose of simulation was to obtain the details of the flowfield,including the structure of the shock wave system,position of flow separation zone,and so on.The performance of the ram-rotor was also evaluated.The numerical results show the structure of the shock wave system in the flow-path is similar to that in the supersonic intake.To improve the overall performance of the ram-rotor,the reasonable compromise between the total pressure ratio and the isentropic adiabatic efficiency should be reached.The structure optimization of the flow-path and the configuration of the shock wave system have great influence on the performance of the ram-rotor.
