In automotive power steering systems it is common practice to include highl
y expandible hoses containing tubular inserts, referred to as tuners, to mi
nimize the pump-generated pressure ripple. A theoretical model of a flexibl
e hose containing a tuner is described, which can be used to compute the fl
uid-borne noise characteristics of complete systems.
Excellent agreement with experimental measurements is obtained. Leakage thr
ough the tuner wall is shown to have a strong effect on the results. With t
he common type of spiral wound tuner, most of the damping present is obtain
ed from this leakage and from energy loss in the hose wall, and for low-vis
cosity fluids it may be acceptable to ignore the effect of fluid viscosity.