What is air mixed with fuel prior to combustion called?

The term used to describe the air that is mixed with fuel prior to combustion is primary air. This mixture is essential for the combustion process because it ensures that there is an adequate supply of oxygen for the fuel to burn efficiently. When fuel is mixed with primary air, it typically occurs in the combustion chamber or burner assembly, where proper mixing is necessary to achieve optimal combustion conditions.

In contrast, secondary air refers to additional air that may be introduced after the initial combustion has started, often to ensure complete combustion and reduce emissions. Combustion air is a broader term that encompasses all air involved in the combustion process, including both primary and secondary air. Excess air is the amount of air supplied to the combustion process above what is strictly necessary for complete combustion; while it is an important consideration for efficiency and emissions, it does not specifically describe the air mixed with fuel before combustion.