In many of the situations especially when fluid flow in tubes, the nature of flow may be pulsatile of peristaltic. in both the cases, the walls are assumed to deform in some specific pattern.

Like what I have learnt so far, In case of pulsatile flow the pressure is assumed to have some sinusoidal nature and then the pattern of velocity and wall deformation is evaluated. Similarly , in peristaltic the motion of wall is assumed to have some specif pattern, say sinusoidal and then velocity and pressure are evaluated.

When to apply what ? Please give your comments.