Assertion: turbine's blade | /r/CapableOf | reduce the lift
Facets:
value: to drag ratio of the airfoil
type: OTHER
value: essentially
type: MANNER
Source sentences:
text: Efficiency can decrease slightly over time, one of the main reasons being dust and insect carcasses on the blades which alters the aerodynamic profile and essentially reduces the lift to drag ratio of the airfoil.