Change in Fuel Consumption and Power settings with increase in altitude.

[S-MAN]

With the increase in Altitude, keeping the IAS constant TAS increases as Density decreases. With decrease in Density, the performance of an aircraft decreases. Thus, at same attitude, to keep same IAS an aircraft would need to produce more thrust.

Would the throttle or power settings needs to be increased?
What effect is dominant on Fuel Consumption, Power or Density?

 

[Itchy]

Every airplane has a sweet spot.

 

[S-MAN]

Every airplane has a sweet spot.

If you don't mind.. Can you please explain below things:

1) With increase in altitude, density decreases which means reduced drag but if the IAS is constant does that mean that the drag will be same but for a higher TAS, as TAS increases with constant IAS with increasing altitude before optimum altitude?

2) With decrease density, fuel consumption is reduced which also gives less aircraft performance and reduce IAS, and to maintain same IAS we need to increase power/thrust?

 

[z987k]

If you don't mind.. Can you please explain below things:

1) With increase in altitude, density decreases which means reduced drag but if the IAS is constant does that mean that the drag will be same but for a higher TAS, as TAS increases with constant IAS with increasing altitude before optimum altitude?

2) With decrease density, fuel consumption is reduced which also gives less aircraft performance and reduce IAS, and to maintain same IAS we need to increase power/thrust?

Yes and yes.

Typically you don't keep a constant IAS on climb. Best rate IAS decreases with altitude, the AoA however, remains constant.

With the increase in Altitude, keeping the IAS constant TAS increases as Density decreases. With decrease in Density, the performance of an aircraft decreases. Thus, at same attitude, to keep same IAS an aircraft would need to produce more thrust.

Would the throttle or power settings needs to be increased?
What effect is dominant on Fuel Consumption, Power or Density?

To maintain a constant IAS in the climb you would have to continually lower the angle you are climbing at because you should already be at full power.
Fuel consumption should be the same for a given power setting (% of max) at any density. There is a point, and in naturally aspirated engines, it's a DA of 0ft, that you no longer can produce 100% power and so power output reduces but so does fuel consumption. Your power setting determines your fuel consumption.