Fluid dampers having temperature-dependent viscosity compensation and auxiliary power unit inlet systems employing the same

A fluid damper configured to be filled with a damping fluid and having an operative temperature range, the fluid damper comprising:

• a housing assembly;
• a first and second hydraulic chambers within the housing assembly, the first hydraulic chamber fluidly coupled to the second hydraulic chamber;
• a variable-length restricted flow path fluidly coupled between first and second hydraulic chamber;
• and
• a viscosity compensator configured to adjust the length of the variable-length restricted flow path in response to variations in the pressure of the damping fluid when the fluid damper is filled therewith to at least partially compensate for thermally-induced changes in the viscosity of the damping fluid and reduce variation in the damping coefficient of the fluid damper over the operative temperature range thereof.

An Auxiliary Power Unit (APU) inlet system, comprising:

• an APU inlet duct;
• an inlet door movable coupled to the APU inlet duct;
• and
• a fluid damper coupled between the inlet door and the APU inlet duct, the fluid damper comprising:
• a housing assembly;
• a first and second hydraulic chambers within the housing assembly, the first hydraulic chamber fluidly coupled to the second hydraulic chamber;
• a variable-length restricted flow path fluidly coupled between first and second hydraulic chamber;
• a viscosity compensator configured to adjust the length of the variable-length restricted flow path in response to variations in the pressure of the damping fluid when the fluid damper is filled therewith to at least partially compensate for thermally-induced changes in the viscosity of the damping fluid and reduce variations in the damping coefficient of the fluid damper over the operative temperature range thereof.