A cyclonic fluid separator has a tubular housing (10) in which the fluid is accelerated and swirl imparting means (2) for inducing the fluid to swirl through an annular space between the housing and a central body (1) mounted within the housing (10), which central body (1) is provided with resonance abatement means, such as: tensioning means (20,22) which apply a tension load to an elongate tail section (8) of the central body (1) such that the natural frequency of the central body (1) is increased; vibration dampening means (31,50,60), which inhibit vibration of at least part (8) of the central body (1); solid particles (31) arranged in a segmented tubular tail section (8) of the central body (1), a viscous liquid (50) arranged between a tubular tail section (8) of the central body (1) and a tensioning rod (51), apertures (60) drilled radially through a tail section (8) of the central body (1); and/or a low pressure fluid (80) injected through a central opening (82) in the central body (1).