Aircraft Powerplant 1 (Reciprocating Engine) PDF

Aircraft Powerplant 1 (Reciprocating Engine) ALIAC PROPERTY Unauthorized Reproduction & Dissemination is prohibited Reciprocating An internal combustion engine that uses one or Engines more reciprocating pistons to convert pressure into a rotati...

Aircraft Powerplant 1 (Reciprocating Engine) ALIAC PROPERTY Unauthorized Reproduction & Dissemination is prohibited Reciprocating An internal combustion engine that uses one or Engines more reciprocating pistons to convert pressure into a rotational motion. Reciprocating engines operate on the basic principle of converting chemical energy (fuel) into mechanical energy. This conversion occurs within the cylinders of the engine through the process of combustion. The two primary reciprocating engine designs are the spark ignition and the compression ignition. ALIAC PROPERTY Unauthorized Reproduction & Dissemination is prohibited  Advantage: Reciprocating Provide incremental electricity quickly Engines High electrical efficiency Quick start-up capabilities, allowing them to start and stop quickly Low pressure gas fuel Can operate at partial loads, with good part load efficiency The characteristics of the exhaust heat makes them great for cabin heating Can start up when grid does not have power Disadvantage: Relatively high emissions Engine cooling produces low grade heat If heat is not used, engine must be cooled High relative maintenance costs ($/MWh) Can have higher levels of low frequency noise TYPES OF RECIPROCATING ENGINE TYPES OF RECIPROCATING ENGINE: In-Line Engine The term “inline engine” is used to refer to a straight engine (an engine with one bank of cylinders).Generally, has even number of cylinders, can be liquid or air cooled and has only one crankshaft. It has Small Frontal area, better adapted to streamlining and has high weight to horsepower ratio. In-Line Engines has multiple configurations: X Type H Type V Type Rolls Royce X-24 H-24 Napier Dagger Liberty L-12 W Type Opposed Piston W-12 Napier Lion Jumo 205 U Type ALIAC Bugatti PROPERTY U-16 Unauthorized Reproduction & Dissemination is prohibited TYPES OF RECIPROCATING ENGINE: V-type Engines Two rows of Cylinders called Banks are arranged in two in-line banks generally set 30,60,90° apart. V-type engines have a reasonable power-to weight ratio with a small frontal area. Because the cylinder banks share a single crankcase and a single crankshaft. V-type Engines Two banks of cylinders typically produce more horsepower than an in-line engine. The pistons can be located either above the crankshaft or below the crankshaft. Most V-type engines had 8 or 12 cylinders and can be either liquid- or air-cooled. Today, V-type engines are typically found on classic military and experimental racing aircraft. ALIAC PROPERTY Unauthorized Reproduction & Dissemination is prohibited ALIAC PROPERTY Unauthorized Reproduction & Dissemination is prohibited TYPES OF RECIPROCATING ENGINE: Radial Engine Consists of a row, or rows, of cylinders arranged radially about a center crankcase. The number of cylinders composing a row may be either three, five, seven, or nine. The two basic types of radial engines are the rotary-type and the static-type. The two basic configurations of radial engines are the single and double row. Rotary-Radial Static-Radial Single-Row Radial Double-Row Radial ALIAC PROPERTY Unauthorized Reproduction & Dissemination is prohibited  TYPES OF RECIPROCATING ENGINE: OPPOSED OF O-TYPE ENGINEINE Opposed-type engines are the most common reciprocating engines currently used on light aircraft. It always have an even number of cylinders, with each cylinder on one side of a crankcase "opposing" a cylinder on the other side. Most opposed engines are air-cooled and horizontally mounted but they can be mounted vertically in helicopters. The compact cylinder arrangement provides a comparatively small frontal area, which enables the engine to be enclosed by streamlined nacelles or cowlings. With opposing cylinders, power impulses tend to cancel each other out ALIAC PROPERTY Unauthorized Reproduction & Dissemination is prohibited SUMMARY: IN-LINE ENGINE OPPOSED OR O-TYPE ENGINE Very compact in design and Horizontally staggered cylinder lightweight. shortening the crankshaft. Moving parts are less compared to Lessens the weight of crankshaft, the engines with multiple cylinder resulting in less power lost to banks. rotational inertia. Less energy is lost which reduces Allows for larger bore diameters and shorter stroke for a given the probability of malfunctions. displacement. Low manufacturing and Low center of gravity allows for better maintenance costs. handling. SUMMARY: V-TYPE ENGINE RADIAL ENGINE Allows for larger bore diameters and shorter Even Cooling of all cylinders since it is directly stroke for a given displacement. The ability to run a shorter stroke also creates exposed to cooling air (at least on single row radials) and can be made lighter and less less of a need to limit rod length. Both factors help with the ability of the engine vulnerable than other configurations. to rev high, as well as improving reliability Uses a small crankshaft- smaller crankcase = while running at high RPMs. reduces weight A longer rod also reduces piston thrust High power to weight ratio. loading, which decreases piston/cylinder wear. Good Visibility for multiengine planes since Shorter crankshaft means fewer problems with engine is mounted way past the cockpit. torsional vibrations. Accessible / Easy to maintain each cylinder. Better balanced than inline engines. WHY ARE THERE DIFFERENT TYPES? OF RECIPROCATING ENGINE ENGINE BALANCE Primary – forces occurring 1x per revolution (reciprocating motion) Secondary imbalance of mass force that is occurring 2x per revolution (Geometry Design of components) WHY ARE THERE DIFFERENT TYPES? OF RECIPROCATING ENGINE Center of gravity Key parameter to determine stability, orientation, braking efficiency and safety Purpose of flight General Aviation Commercial Aviation Passenger Cargo Military Aviation WHY ARE THERE DIFFERENT TYPES? OF RECIPROCATING ENGINE Operating Cost Type of Fuel used Tires Maintenance & Repair Registration & Insurance Business Innovation Affordable Limited Edition Engine Requirements: Small general aviation aircraft use mostly horizontally opposed reciprocating piston engines while some aircraft still use radial reciprocating piston engines however, their use is very limited. All aircraft engines must meet certain general requirements of efficiency, economy, and reliability. Besides being economical in fuel consumption, an aircraft engine must be economical in the cost of original procurement and the cost of maintenance; and it must meet exacting requirements of efficiency and low weight-to- horsepower ratio. ALIAC PROPERTY Unauthorized Reproduction & Dissemination is prohibited  Engine Requirements: EFFICIENCY Every excess pound of weight carried by an aircraft engine Power and Weight: If the specific weight of an reduces its performance. engine is decreased, the performance of the aircraft will increase. Tremendous improvement in Reciprocating engines produce approximately reducing the weight of the aircraft 1HP for each pound of weight. engine through improved design and metallurgy has resulted in reciprocating engines with a much- improved power-to-weight ratio (specific weight). ALIAC PROPERTY Unauthorized Reproduction & Dissemination is prohibited Engine Requirements: FUEL ECONOMY The basic parameter for describing the fuel economy of aircraft engines is specific fuel consumption. Specific fuel consumption for reciprocating engines is the fuel flow (gal | lbs/hr) divided by brake horsepower. Comparisons can be made between the various engines on a specific fuel consumption basis. At low speed, the reciprocating and turboprop engines have better economy than the pure turbojet or turbofan engines. At high speed, because of losses in propeller efficiency, the reciprocating or turboprop engine’s efficiency becomes limited above 400 mph less than that of the turbofan. ALIAC PROPERTY Unauthorized Reproduction & Dissemination is prohibited Engine Requirements: RELIABILITY An aircraft engine is reliable when it can perform at the specified ratings in widely varying flight attitudes and in extreme weather conditions. The engine manufacturer ensures the reliability of the product by design, research, and testing. Close control of manufacturing and assembly procedures is maintained, and each engine is tested before it leaves the factory. ALIAC PROPERTY Unauthorized Reproduction & Dissemination is prohibited Engine Requirements: DURABILITY Durability is the amount of engine life obtained while maintaining the desired reliability. However, no definite time interval between overhauls is specified or implied in the engine rating. The time between overhauls (TBO) varies with the operating conditions, such as engine temperatures, amount of time the engine is operated at high-power settings, and the maintenance received. Recommended TBOs are specified by the engine manufacturer. ALIAC PROPERTY Unauthorized Reproduction & Dissemination is prohibited Engine Requirements: OPERATING FLEXIBILITY The ability of an engine to run smoothly and give desired performance at all speeds from idling to full-power. The engine must also function efficiently through all variations in atmospheric conditions. ALIAC PROPERTY Unauthorized Reproduction & Dissemination is prohibited Engine Requirements: COMPACTNESS To effect proper streamlining and balancing of an aircraft, the shape and size of the engine must be compact. In a single engine aircraft, the shape and size of the engine will affect the view of the pilot and in addition to reducing the drag created by a large frontal area. Weight limitations, naturally, are closely related to the compactness requirement. The more elongated and spread out an engine is, the more difficult it becomes to keep the specific weight within the allowable limits. ALIAC PROPERTY Unauthorized Reproduction & Dissemination is prohibited