A Brief Explanation Of The Internal Combustion Engine

Internal Combustion engine can be defined as, “An engine in which a fuel-air mixture is burnt so that the hot gaseous products of the resultant combustion act directly on the surface of its moving parts.”

Internal-combustion engines comprises of diesel engines, gasoline engines, gas turbine engines, pure jet engines, motor engines and rocket engines. They are further sub-divided into continuous-combustion engines and intermittent-combustion engines. In the first type, the fuel and airflow steadily into the engine and a stable flame is maintained for continuous combustion. In the second type, certain quantities of fuel and air are ignited.

Internal combustion engines are generally used for propulsion in automobiles, equipments etc. These engines are used in jet aircrafts, helicopters etc.

All internal combustion engines depend on the certain chemical processes. The common modern fuels are made up of a hydrocarbon which is a product of petroleum. Fuels such as diesel fuel, gasoline and petroleum gas are part of this. All internal combustion engines should be able to ignite in their cylinders in order to create combustion. Most engines use either an electrical method or a compression ignition system.

There are two main types of model airplane engines. The glow engines and diesel engines.
The diesel engine is an internal combustion engine which is the compression ignition, i.e. when the fuel is ignited; it is injected into air in the combustion chamber that is compressed to certain temperatures and it causes the ignitions.

The diesel engine is generally not used in an aircraft engine. Though it has excellent fuel consumption techniques, it has many disadvantages as compared to gasoline-fueled or turboprop engines.

Some of the characteristics of diesel engines are:

• They need a supply of suitable fuel to work.
• They are heavier and stronger than glow engines, and they last longer.
• They vibrate more and are less responsive to throttle control than glow engines, and so they are not good for operating radio-controlled models.
• They cannot operate fast like a glow engine, and so their competitive value is quite less.
• They are excellent power units for small and medium sized 'sports models’ and certain types of control-line models.
• Diesel engines are available in a more range of sizes than glow engines. Very small diesel engines are quite difficult to make, start or adjust.
• Diesel engines larger than about 3.5cc do not have good performance. So its production is limited to the smaller sizes.

Some Of The Characteristics Of Glow Engines Are:

• Glow engine are more in number popular, faster and powerful. They are suited for all types of model aircrafts and are produced in three categories like standard engines; racing engines; and Radio Controlled engines.
• They need a specific type of ignition plug or glow plug. Frequent replacements are needed as they burn out soon.
• In addition, a battery is connected to the plug for starting, and special expensive alcohol-based fuels are required.
• Glow engines affect the paints and cellulose dope finishes. Due to this reason, model crafts need fuel proof paints.