In contrast, for compressible flow, is variable and becomes an unknown. Hence we need an additional equation the energy equation-which in turn introduces internal energy e as an unknown 对于可压缩流,相反的是 是一个变量 并且是一个未知数.因此,我们需要一个附加 方程一能量方程一进而引入未知数肉能 Internal energy e is related to emperature then T also becomes an important variable Therefore, the 5 primary dependent variables are v,p, e, and T To solve for these me vorable s, we need ne governingIn contrast, for compressible flow, is variable and becomes an unknown. Hence we need an additional equation – the energy equation – which in turn introduces internal energy e as an unknown. 对于可压缩流，相反的是 是一个变量， 并且是一个未知数． 因此，我们需要一个附加 方程－能量方程－进而引入未知数内能e。 Internal energy e is related to temperature, then T also becomes an important variable. Therefore, the 5 primary dependent variables are: To solve for these five variables, we need five governing equations  p,V, , e, and T  