Reciprocating Engine - Intro

The force needed to move an aircraft, either for flight or takeoff.

A type of heat engine used in aircraft to generate thrust.

A device that converts heat energy into mechanical energy.

The resistance an aircraft experiences due to air.

The forward force needed to propel an aircraft through the air.

The force that pushes an aircraft forward, overcoming drag and weight for flight.

Thrust must equal and oppose the aircraft's drag to maintain a steady altitude.

Fuel, air, and spark create heat energy within the engine to power movement.

For every action, there's an equal and opposite reaction.

Rockets carry their own oxidizer and expel exhaust at high velocity to propel themselves.

Propellers accelerate a large mass of air at relatively lower velocity to generate thrust.

A broader class of engines, including turboprops, turbojets, turbofans (and more) that use a gas turbine to produce thrust.

Important factors to consider in the design of aircraft engines, including fuel efficiency, power, and safety.

Aircraft engines must meet specific requirements like efficiency, economy, reliability, compactness, vibration reduction, and wide power output range.

Means low weight-to-horsepower ratio, which implies a powerful engine that doesn't weigh a lot.

Refers to both fuel consumption and cost of production and maintenance.

Means consistent high power output without compromising reliability, ensuring long operating periods between overhauls.

Engines must be small for space efficiency but still maintain easy accessibility for maintenance.

Engines need systems to dampen vibrations to ensure smooth operation and passenger comfort.

Engines must deliver power efficiently at different speeds and altitudes.

Provides pressurized oil to lubricate and cool engine parts while operating.

Generates a spark to ignite the fuel in the engine's cylinders, delivering the spark under various conditions.

Provides the right fuel/air mixture to the engine regardless of aircraft position, altitude, or weather.

Thrust, the force that propels the aircraft, is measured in thrust horsepower for gas turbine engines, while brake horsepower is used for reciprocating engines.

Power is calculated by Force multiplied by distance divided by time.

Aircraft engines often operate at high power percentages, especially during takeoff.

Reducing engine weight per horsepower increases the aircraft's performance and payload capacity.

Measured by specific fuel consumption, which is fuel flow divided by horsepower.

A type of reciprocating engine with cylinders arranged in a circle around a central crankshaft. It's known for its ruggedness and reliability, though its use is limited today.

An early type of internal combustion engine where the cylinders rotate around a fixed crankshaft. This design led to stability issues and high fuel/oil consumption.

The tendency of a rotating object to resist changes in its rotation axis. In rotary engines, this effect caused stability problems.

A type of oil used as a lubricant in early rotary engines, known for its unfortunate side effects.

Pilots often inhaled and swallowed a considerable amount of castor oil during flight, which led to persistent diarrhea and oily clothing.

Rotary engines were typically run at full throttle and had less-than-ideal valve timing, leading to inefficient fuel use.

Primitive carburetion systems in rotary engines mixed lubricating oil with fuel, leading to high oil consumption and smoky exhaust.

A device that forces more air into an engine's cylinders, increasing power output.

A device that uses exhaust gases to spin a turbine, which drives a compressor that forces more air into the engine.

The ratio of the volume of air in an engine cylinder before compression to the volume after compression.

The engine manufacturer provides recommendations on the types of TBOs (Time Between Overhauls) for their engines.

Engine failure is infrequent due to careful maintenance, regular inspections, and adherence to operating limits.

Aircraft engines can be grouped based on various features like operating cycles, cylinder arrangement, thrust generation, and production methods.

Most modern aircraft engines are internal combustion engines, where fuel burns inside the engine to create power.

Engine types include gas turbine, reciprocating piston, rotary, two or four cycle, spark ignition, diesel, air cooled, and water cooled.

This type of engine features a piston that moves back and forth, converting combustion energy into mechanical power.

Reciprocating piston engines can be classified by how their cylinders are arranged, including inline, V-type, radial, and opposed configurations.

All piston engines rely on air to cool them, but air-cooled engines have fins that increase surface area for better heat dissipation.

Some high-performance engines use a liquid-cooling system for more efficient heat removal compared to air cooling.

An inline engine has cylinders arranged in a single row, typically with an even number, and uses a single crankshaft.

Inline engines offer shorter landing gear, better pilot visibility, and small frontal areas for improved streamlining.

Inline engines can have poor cooling for cylinders at the back, especially in air-cooled configurations, and their long crankshaft can be prone to twisting.

A V-type engine features two banks of cylinders arranged in a V-shape, typically with a 60° angle between them.

Radial engines can be single-row (one row of cylinders) or multi-row (two or more rows of cylinders) and come in various cylinder counts.

Two rows of cylinders arranged around the crankcase, one in front of the other, are known as double row radials.

A reciprocating engine with two banks of cylinders directly opposite each other, connected to a single crankshaft in the center.

Opposed engines offer low vibration, a narrow silhouette, and a good weight-to-horsepower ratio.

Opposed engines are commonly used in aviation, especially in air-cooled versions.

The foundation of a reciprocating engine, containing bearings and supporting the crankshaft.

The crankcase provides a tight enclosure for oil, supports mechanisms, attaches cylinders, and connects the engine to the aircraft.

Precisely machined surfaces on the crankcase that allow for secure attachment of cylinders.

The lower part of the cylinder that extends into the crankcase, helping to prevent oil from entering the cylinders.

Lugs on the crankcase that attach the engine assembly to the aircraft's mount.

The framework used to attach the engine to the aircraft, providing a secured and rigid connection.

The rear part of the engine that houses accessories like magnetos, pumps, and starters.

Shafts that connect to gears to drive the engine's accessories at the correct speeds.

Used in accessory gear trains to drive heavy-loaded accessories and reduce backlash.

Used in gear trains to allow for angular location of accessories and shafts.