What is an Engine ? and how engines are classified ?

        A heat engine is a device that converts heat energy into mechanical work. The chemical energy of a fuel is converted into heat energy by combustion of fuel to produce work expansion.

Heat Engine has two types:-

1. External Combustion Engine

   This is an engine, where the combustion of air & fuel takes place outside the cylinder using secondary fuel.

2. Internal Combustion Engine

   This is an engine, where the combustion of air and fuels take place within the cylinder and are used to convert chemical energy to mechanical.

Let's see the classification of each-

1. External Combustion Engine

External Combustion Engine Classification

2. Internal Combustion Engine

Internal Combustion Engine Classification 

• Detailed Classifications of IC Engine
  1. According to no. of strokes-
  1. Two-Stroke cycle engine
  2. Four-Stroke cycle engine
  2. According to combustion cycle used-
  1. Otto cycle (constant volume cycle)
  2. Diesel cycle (constant pressure cycle)
  3. According to no. of cylinders-
  1. Single cylinder 
  2. Multi-cylinder
  4. According to the arrangement of cylinders-
  1. Horizontal engine
  2. Vertical engine
  3. V-type engine
  4. Inline engine
  5. Radial engine 
  5. According to ignition method-
  1. Spark ignition 
  2. Compression ignition
  6. According to the cooling method-
  1. Air-cooled
  2. Water-cooled
  7. According to the speed of Engine-
  1. Low-speed engine
  2. Medium-speed engine 
  3. High-speed engine
  8. According to the type of fuel used-
  1. Petrol engine
  2. Diesel engine 
  3. Natural Gas engine (CNG or LPG)
  4. Bio-fuel engine
  5. Light oil (kerosene) engine
  6. Alcohols (methanol or ethanol)
  7. Hydrogen engine 
  9. According to mixture preparation -
  1. Carburetion
  2. Fuel injection into port or intake manifold 
  3. Fuel injection into the engine cylinder
  10. According to the valve or port design & location-
  1. Overhead valve
  2. Underhead valve
  3. Rotary valve
  4. Cross-scavenged porting
  5. Loop-scavenged porting
  6. Uniflow-scavenged
  11. According to the uses of application-
  1. Stationary engine
  2. Portable engine
  3. Marine engine
  4. Automobile engine
  5. Tractor engine
  6. Aero-engine
• Quick Recall for classification of IC Engine-
• S-strokes
• C-combustion 
• C-no. of cylinders
• A-arrangement of cylinder
• I-ignition method
• C-cooling method
• S-speed of engine
• F-fuel used
• M-mixture preparation
• V-valve/port design & location 
• A-application 
• "SCAM ICC FAVS" - remember this