This example shows the behavior of a constant volume chamber with rigid or compliant walls. The chamber is placed between two linear hydraulic resistances and subjected to an abrupt change in supply pressure at the beginning of simulated time range. The chamber is a piece of a steel cylindrical pipe of 0.03 m internal diameter, 0.036 m external diameter, and 16.5 m length. The chamber characteristics are investigated by changing air content in the fluid, by switching from rigid to compliant walls, and by changing wall compliance and pipe viscoelasticity time constant.
If the chamber wall is set to rigid and the amount of entrapped air is zero, the pressure change at the chamber inlet can easily be determined analytically and simulated with the Simulink® Transfer Fcn block. By comparing pressures at the outputs of SimHydraulics® and Simulink® blocks, (1) the accuracy of the block can be assessed and (2) the influence of the block parameters on chamber behavior can be estimated.