Conservation Equations in a Flow Field

Let us consider a simplified flow, that is, a one-dimensional steady-state flow-without viscous stress or a gravitational force. The conservation equations of continuity, momentum, and energy are represented by rate of mass in - rate of mass out = 0 

Combining Eqs. (1.20) and Eq. (1.4), one obtains the relationship for the enthalpy change due to a change of flow velocity as 

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