can drag force be used in producing electricity when da a/c is flying?

Question

hi i m ashish sharma doing aircrft engineering
is there any way we can use drag force to produce electricity
while da a/c is flying as d afriction can be used to produce electricitu so may be we can use drag......

Answer 1

Sure many aircraft take electrical power off the turbines once the engines are running. However you don't want to add anything that will produce additional drag.

Answer 2

The second law of thermodynamics states that you cannot do work on a system by extracting energy from it. Sure, an aircraft may use the headwind to drive a turbine to produce electrical energy, but the energy spent in keeping the aircraft flying will always be greater than the energy that can be extracted from the foerward flight. The larger any turbine generator was, the greater the enrgy requirement would be to keep the aircraft in forward flight. Eventually, if the turbine was large enough, the plane would not fly at all, and there would be no energy to extract.

A similar argument has been used in proposing that a ship travelling through the ocean could extract heat from the seawater to drive a turbine to provide forward motion. Again, the energy spent in extracting the heat would be greater than the energy extracted.

Answer 3

Yeah. It's called a windmill. Like the first poster said, it will add more drag and waste fuel.