Mostafa Mir-Salim, head of the conference, said internal combustion engines have rendered valuable services to mankind in the past century. 

However, he said, these engines cause heavy air pollution due to using fossil fuels. 

Vahid Hosseini, scientific secretary of the conference, said more than 187 articles were submitted to the event, 107 of which were accepted. 

The term internal combustion engine usually refers to an engine in which combustion is intermittent, such as the more familiar four-stroke and two-stroke piston engines, along with variants, such as the six-stroke piston engine and the Wankel rotary engine. A second class of internal combustion engines use continuous combustion: gas turbines, jet engines and most rocket engines, each of which are internal combustion engines on the same principle as previously described.