2. Mathematica| Model(数学模型) For flow in duct with variable cross-sectional area it is necessary to use differential equations to reveal the relationships between 1.C ◆ Conservation Equation of Mass〔质量守恒方程) ◆ Conservation Equation of Energy(能量守恒方程) Equation of State(状态方程) For ideal as(对理想气体) PeRT 4y-=0fp,=0 For real gas(对实际气体) ◆Pr。 cess Equation(过程方程) ◆ Equation of Entr。py(熵方程)2. Mathematical Model (数学模型） For flow in duct with variable cross-sectional area, it is necessary to use differential equations to reveal the relationships between Conservation Equation of Mass (质量守恒方程） Conservation Equation of Energy (能量守恒方程） Equation of State (状态方程) For Ideal Gas (对理想气体） For Real Gas (对实际气体) ◆ Process Equation (过程方程） Equation of Entropy(熵方程） p,v,T,m  ,c, f