How does a turbine engine generate thrust differently from a piston engine?

• A. A turbine engine converts chemical energy of fuel into kinetic energy of exhaust to produce thrust
• B. A turbine engine uses a crankshaft to drive a propeller
• C. Both rely on external airflow to generate thrust
• D. Turbine engines create thrust by electrical means

Answer: (A)

A turbine engine generates thrust by converting the chemical energy of fuel directly into kinetic energy of the exhaust jet. The combusted fuel accelerates the exhaust gases out the back, and the high-speed jet pushes the aircraft forward in reaction. A piston engine, by contrast, uses the energy of combustion to move pistons and turn a crankshaft, and this mechanical power is used to drive a propeller. The propeller then accelerates a large mass of air to create thrust from the reaction force on the blades. So the turbine’s thrust comes from accelerating the exhaust, while the piston engine’s thrust comes from turning a propeller to push air. The other statements don’t fit: a turbine engine does not rely on a crankshaft to drive a propeller in the same way piston engines do, turbine thrust isn’t created by electrical means, and while both interact with airflow, the core mechanism differs.