A throttle is typically some form of abrupt restriction to [[Fluid|fluid]] flow. As a result, a very quick [[Pressure|pressure]] drop will occur. There is no output [[Work|work]] and negligible [[Heat|heat]] transfer for a throttling process. Therefore the process is assumed to be a pressure drop at constant [[Enthalpy|enthalpy]]. ![[throttle.png|center|500]] Equation Summary: | Conservation Item | Condition | Result | | -------------------- | -------------------- | --------------------- | | Heat | Adiabatic | $\dot{Q}=0$ | | Work | Zero work | $\dot{W}=0$ | | Enthalpy | Negligible | $\Delta H=0$ | | Kinetic | Typically negligible | $\Delta K=0$ | | Potential | Typically negligible | $\Delta P=0$ | | Mass Conservation | | $\dot{m}_i=\dot{m}_e$ | | Pressure | Decreases | $P_2<P_1$ | | Total Energy Balance | | $h_1=h_2$