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L/D
Usado para
lift-to-drag ratio
Definição1
L/D Ratio of total lift to total drag, fundamental measure of effiiency of aircraft; L is normally constant and equal to weight but drag varies approx as square of airspeed; thus L/D plot is curve with peak at one particular airspeed for each aircraft, L/Dmax.
Fonte1
GUNSTON, Bill. The Cambridge aerospace dictionary. Cambridge: Cambridge University, 2004. (Cambridge aerospace series.)
Fonte2
INTERNATIONAL CIVIL AVIATION ORGANIZATION. Report by the second CAEP noise technology independent expert panel: novel aircraft-noise technology review and medium- and long-term noise reduction goals: report. Montreal, 2014. (Doc. 10017).
Fonte3
INTERNATIONAL CIVIL AVIATION ORGANIZATION. Report of the independent experts on the medium and long term goals for aviation fuel burn reduction from technology. Montreal, 2010. (Doc. 9963).
Contexto
The EPNL at the flyover measuring point depends on the effective jet speed at cutback for an airspeed of V2+20 kts and the flyover altitude. The latter depends on the take-off field length, the initial climb ratio and the climb ratio at the flyover point. The climb ratios depend on the thrust-to-weight ratio and the lift-to-drag ratio. The field length depends on thrust-to-weight ratio and V2 speed of the aircraft.
It was found that the different calculations of fuel burn for the baseline aircraft agreed reasonably well in terms of absolute kg/ATK but it was also found that if the precise inputs were matched (e.g. lift/drag ratio, empty weight/maximum take-off weight, engine specific fuel consumption, reserve fuel assumptions) then the agreement in absolute values was very close even when different models were used.
As already noted, in Figure 2.1 all parameters related to the technology level of the aircraft (lift/drag ratio, engine specific fuel consumption, empty weight/maximum take-off weight) are held constant for this comparison.
Related Term
L/D MAX
Português
curva de sustentação vs. arrasto