Deflector

[dɪ'flɛktɚ]

(noun.) a device intended to turn aside the flow of something (water or air or smoke etc).

Inputed by Cornelia--From WordNet

(n.) That which deflects, as a diaphragm in a furnace, or a cone in a lamp (to deflect and mingle air and gases and help combustion).

Checked by Enrique