Does afterburner use more fuel?

Afterburning significantly increases thrust as an alternative to using a bigger engine with its attendant weight penalty, but at the cost of very high fuel consumption (decreased fuel efficiency) which limits its use to short periods.

How efficient is an afterburner?

In the afterburner, the fuel flow is m ˙ f =1.00 kg/s. The bypass duct burner flow is assumed to mix internally with the turbine exit flow with the resulting stagnation pressure being the average of the two. The combustion efficiency is 0.85, and frictional losses in the afterburner yield (pt,5 − pt,5AB) = 0.05pt,5F.

How much fuel does a afterburner use?

In the dense air at sea level with maximum afterburner selected and at high speed, the total fuel flow can be more than 23,000 gallons per hour, or 385 gallons per minute. At this rate you would burn through your entire internal fuel load in about 6 minutes.

What is the advantage of an afterburner?

The big advantage of an afterburner is that you can significantly increase the thrust of the engine without adding much weight or complexity to the engine. An afterburner is nothing but a set of fuel injectors, a tube and flame holder that the fuel burns in, and an adjustable nozzle.

How long can a jet use afterburner?

In full afterburner at low altitudes, the F-16 can burn in excess of 64,000 pounds an hour. At full throttle, a U.S.-variant F-16 with maximum external fuel stores has about 20 minutes until it’s on emergency reserves (which would only last an extra minute or so at full afterburner).

How hot is a jet afterburner?

1700 deg. C
Since the temperature of an afterburner can reach 1700 deg. C, the flame is usually concentrated around the jet pipe axis, allowing a portion of the discharge gas to flow along the wall of the jet pipe and therefore maintain a safe wall temperature.

Are fighter jets fuel efficient?

Capable of sustaining supersonic speed without afterburners, the fighter jet gets an estimated . 4 mpg, depending on conditions and speed, which tops out at Mach 2. Like many military aircraft, these planes are capable of midair refueling, but that gets even more expensive.

How much fuel can a fighter jet hold?

Each conformal tank can hold 750 U.S. gallons (2,840 L) of fuel. These CFTs increase range and reduce the need for in-flight refueling. All external stations for munitions remain available with the tanks in use.

Which aircraft has highest propulsive efficiency?

This is shown qualitatively by figure 65. The propeller is the most efficient propulsive method at low speeds, while the jet engine achieves best efficiency only at relatively high flight speeds. The very high exhaust velocities of the rocket make its propulsive efficiency high only at very high flight speeds.

What is a jet engine afterburner and how does it work?

A jet engine afterburner is an extended exhaust section containing extra fuel injectors. Since the jet engine upstream (i.e., before the turbine) will use little of the oxygen it ingests, additional fuel can be burned after the gas flow has left the turbines. When the afterburner is turned on, fuel is injected and igniters are fired.

What is the maximum thrust a jet can produce with afterburner?

Maximum thrust with afterburner 15,660 daN (each 7’830 daN) Some airplanes need the afterburner to reach supersonic speed because the “normal” use of the jet turbine doesn’t generate enough thrust. Using the turbine in “normal” mode (without afterburner) is also called “military power” or “dry”.

What is the difference between afterburner turbojet and dump and burn?

A turbojet engine equipped with an afterburner is called an “afterburning turbojet”, whereas a turbofan engine similarly equipped is sometimes called an “augmented turbofan”. [citation needed] A ” dump-and-burn ” is a fuel dumping procedure where dumped fuel is intentionally ignited using the plane’s afterburner.

What happens to the fuel in a turbojet engine?

The fuel burns and produces additional thrust, but it doesn’t burn as efficiently as it does in the combustion section of the turbojet. You get more thrust, but you burn much more fuel. With the increased temperature of the exhaust, the flow area of the nozzle has to be increased to pass the same mass flow .