blowdown

(chemical engineering) The removal of liquid and solid hydrocarbons from a refinery vessel by the use of pressure.

(industrial engineering) Cooling fluid discharged from a plant at the end of its cycle.

(forestry) Uprooting, overtopping, or bole breakage of trees by the wind; windthrow and windsnap.

(aviation) The action of aerodynamic forces to tend to cause a deflected control surface to return to its neutral position, or prevent the surface from deflecting past a certain point.