Flow sensor assembly with porous insert

The present disclosure relates generally to flow sensors, and more particularly, to methods and devices for reducing variations in fluid flow (14) across the flow sensor (10) for increased accuracy and/or reliability. In one illustrative embodiment, a flow sensor assembly 30 includes a housing 36, 37 with an inlet flow port 32 and an outlet flow port 34. The housing defines a fluid channel (12) extending between the inlet flow port 32 and the outlet flow port 34, with a flow sensing element 42 positioned in the housing and exposed to the fluid channel. A porous polymer insert 22 is situated in the fluid channel upstream of the flow sensor. The porous insert 22 is configured to reduce the turbulence in the fluid passing the flow sensor and enhance a laminar flow profile of the fluid. A porous insert 24 may also be provided downstream of the sensor. The flow sensor may comprise, for example, one or more thermal sensors or pressure sensors.