How do afterburners affect engine performance and fuel consumption?

How do afterburners affect engine performance and fuel consumption?

• A. Provide additional thrust by burning extra fuel in exhaust; dramatic increase in fuel consumption and heat.
• B. Increase efficiency and reduce fuel usage.
• C. Cool the exhaust to protect turbine blades.
• D. Decrease engine noise.

Answer: (A)

Afterburners work by injecting extra fuel into the exhaust and igniting it, which adds energy to the jet flow and increases thrust beyond what the engine alone can produce. This thrust boost comes at a steep cost: fuel flow increases dramatically and exhaust heat rises, making afterburning extremely fuel-inefficient and heat-intensive. For this reason, afterburners are used only for short periods during high-demand maneuvers, not for normal operation. The other descriptions don’t fit: cooling the exhaust, improving efficiency, reducing fuel use, or quieting the engine would not occur with an afterburner; in fact, it increases heat and usually noise.

Afterburners work by injecting extra fuel into the exhaust and igniting it, which adds energy to the jet flow and increases thrust beyond what the engine alone can produce. This thrust boost comes at a steep cost: fuel flow increases dramatically and exhaust heat rises, making afterburning extremely fuel-inefficient and heat-intensive. For this reason, afterburners are used only for short periods during high-demand maneuvers, not for normal operation. The other descriptions don’t fit: cooling the exhaust, improving efficiency, reducing fuel use, or quieting the engine would not occur with an afterburner; in fact, it increases heat and usually noise.