Do You Know How Automotive Exhaust Systems Work?

How does exhaust work?
Exhaust is not only that thing, which sounds awesome. This is a quite complicated system, which consists from different parts. I would name them different elements. Basically, Exhaust system consist form: exhaust manifold, catalytic converter, resonator, and muffler, connected to the tailpipe. Exhaust gas is evacuated in manifold through exhaust valves.After this exhaust gas passes through a pipe in the catalytic converter. Hot gasses are entering the catalytic converter, and here magic begins. Due to partial combustion, the gasses, entering the catalytic converter consists of a mixture of carbon monoxide (CO), Unburned Hydrocarbons and Nitrogen oxides, which are harmful to the environment.

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Inside the converter there are two ceramic block with ducts, made of Platinum and Rhodium one block and Platinum and Palladium another block, those materials are acting like catalysts. Because of high temperature toxic gas interacts with catalyst materials. Gas enters inside and first are reacting Nitrogen oxides, catalyst is splitting Nitrogen oxide in nitrogen and oxygen. After this gas flows towards second block, where it react with Platinum and Palladium.

Do You Know How Automotive Exhaust Systems Work?

In the second block, Carbon Monoxide grabs one more molecule of oxygen and becomes CO2 Carbon Dioxide. Hydrocarbons are becoming water and carbon dioxide. Less toxic gas exits catalytic converter it consists of Carbon Dioxide, Nitrogen and Water Vapors. It is not so toxic, but quite loud, because of sound waves, generated by the engine. In order to reduce this sound, gases flows through muffler. The muffler is a complicated system, it consists of different size chambers. The first chamber is called expansion chamber, this is the first place where gas enters. It consists of drilled holes around its surface. Some of the waves are moving out of these holes and moving back and forth against the walls of the muffler. As more waves are coming out the space of movement reduces, which causes friction and ultimately destroys the wave. Sound waves are passing in the second Chamber. Here is the same system waves are destroyed due to lack of the space. Loudest sound waves, if they passed two chambers before, – they are ready to enter Helmholtz Resonator. Here sound waves are hitting the wall of the Helmholtz sound waves are reflected and generates opposite wave, and this means that sound waves are canceling each other.

But before gas escape from the muffler it must pass through the third chamber.Only after that gas passes in tailpipe.