5.稳态稳定流动( Steady- flow process) a process during which a fluid flows through a control volume steadily. That is,the properties remain the same at a fixed point during the entire process
5.稳态稳定流动(Steady-flow process) A process during which a fluid flows through a control volume steadily. That is, the properties remain the same at a fixed point during the entire process
6循环( Cycle) If a system returns to its initial state at the end of the process it is said a system have undergone a cycle. 系统经历了一系列状态变化过程,又回到了原来状态, 称为热力循环
6.循环 (Cycle) If a system returns to its initial state at the end of the process, it is said a system have undergone a cycle. 系统经历了一系列状态变化过程，又回到了原来状态， 称为热力循环
7比热容( Specific Heat) 将单位物量的物质温度升高1K所需加入的热量 the energy required to raise the temperature of a unit quantity of a substance by one degree
7.比热容（Specific Heat) 将单位物量的物质温度升高1K所需加入的热量。 The energy required to raise the temperature of a unit quantity of a substance by one degree
8分容积( component volume) 假定混合气体中组成气体具有与混合气体相 同的温度及压力时,单独存在所占有的容积。 9分压力( Component pressure) 假定混合气体中组成气体单独存在,并具有 与混合气体相同的温度及容积时的压力
8.分容积 ( component volume ) 假定混合气体中组成气体具有与混合气体相 同的温度及压力时，单独存在所占有的容积。 9.分压力（Component pressure） 假定混合气体中组成气体单独存在，并具有 与混合气体相同的温度及容积时的压力
10焓( Enthalpy) Enthalpy, a state function is defined as follows hsu+ pv This energy is composed of two parts: the internal energy of the fluid(u and the flow work (pv)associated with pushing the mass of fluid across the system boundary. 对开口系统而言,焓指流动工质所携带能量的一部 分,这部分能量取决于热力状态
10.焓（Enthalpy） Enthalpy, a state function, is defined as follows, h= u + pv This energy is composed of two parts: the internal energy of the fluid (u) and the flow work (pv) associated with pushing the mass of fluid across the system boundary. 对开口系统而言，焓指流动工质所携带能量的一部 分，这部分能量取决于热力状态