What term is generally used for a device that helps start combustion by mixing a fuel with air?

The term commonly used to refer to a device that initiates combustion by mixing fuel with air is a "burner." A burner is designed to create the right conditions for fuel and air to mix efficiently, facilitating the combustion process. It operates by providing a controlled environment where the fuel can vaporize and combine with air, leading to ignition and allowing for sustained burning.

In contrast, an ignition source is typically associated with the element that provides the initial spark or heat necessary to ignite the fuel-air mixture. This could refer to a spark plug or flame used to begin combustion, but it does not directly mix fuel and air. A combustion engine refers to a broader mechanical system that utilizes combustion for various types of work, while a flame initiator does suggest the starting of a flame but lacks the specific function of mixing fuel with air in the way a burner does.