Solution

Solve the differential equation for small channel areas $A(t)\Longrightarrow$

$$\frac{dU}{dt} = \frac{\sqrt{2}A(t_0)^{\frac{1}{2}}}{\rho}[p_0(t_0... ...\frac{3}{2}} \cdot \frac{1}{1 + \frac{U(t_0) T}{\sqrt{2} A(t_0)^{\frac{3}{2}}}}$$

``Feathering term'' $U(t_0) T / \sqrt{2} A(t_0)^{\frac{3}{2}}$ reduces volume flow derivative in the presence of small channel areas $A(t)$ and large sampling periods $T$, giving a more accurate volume flow and reducing aliasing.