The Exhaust Manifold is a pipe that collects exhaust gases from many cylinders into a single pipe. The term “manifold” comes from the Old English word manigfeald, which means “folding together multiple inputs and outputs”. The exhaust manifold is a crucial part of an engine’s system because it keeps the engine’s performance and efficiency high.
To analyze the working process of an exhaust manifold, it is necessary to consider its thermal characteristics. The exhaust manifold’s heat transfer coefficients depend on the temperature and pressure. Therefore, a model that considers the temperature and pressure conditions inside the manifold is required to accurately analyze its thermal characteristics.
The materials used for an exhaust manifold need to resist corrosion and fatigue under repeated thermal stresses. The material should also be resistant to oxidation and inhomogeneous corrosion, which reduces the thickness of the manifold’s walls. This process also creates corrosion residue that damages the catalyst and turbine wheel.
An exhaust manifold is generally made of stainless steel or cast iron and collects exhaust gas from several cylinders. It then directs it to the exhaust pipe. There are aftermarket tubular exhaust manifolds available for many vehicles. These are referred to as “headers” or “exhaust manifolds” in American and British English, and are often installed to customize a car’s performance.
Exhaust manifolds are typically made of metal to prevent thermal shock. They are generally made of alloy steel to withstand high temperatures and high stresses. Moreover, they are often equipped with a basic cooling system that helps reduce their temperature. In most cases, the cooling system is a recirculating water jacket that siphons heat away from the tubes. While water is the most common coolant, other types of liquids can be used.