What characterizes a lean mixture in terms of gas and air?

A lean mixture is characterized by having more air and less gas compared to a stoichiometric or rich mixture. In combustion engines, fuel and air must be mixed together for efficient combustion. When there is an excess of air relative to the amount of fuel, the mixture is considered lean. This condition results in more oxygen being available for combustion, which can improve fuel efficiency and reduce emissions.

In practical terms, a lean mixture allows for more complete combustion, which can lead to higher engine efficiency and lower hydrocarbon emissions from the exhaust. However, it also requires careful balance, as too lean of a mixture can lead to incomplete combustion, misfires, or even engine damage due to excessive temperatures.

Understanding the components of a lean mixture helps in various applications across aerospace and automotive industries where fuel efficiency and emission controls are critical aspects of design and operation.