Volume Flow

Figure 25: The clarinet Reed.

• The steady flow through a valve is determined based on input pressure $p_1$ and the resulting output pressure $p_2$.
• The difference between these two pressure is denoted $\Delta p$ and is related to volume flow via the stationary Bernoulli equation
  $$U = A\sqrt{\frac{2\Delta p}{\rho}},$$
  where $A$ is the cross section area of the air column (and dependent on the opening $x$).

Figure 26: The reed table.