Zeldovich–Liñán–Dold model
In combustion, Zeldovich–Liñán–Dold model or ZLD model or ZLD mechanism is a two-step reaction model for the combustion processes, named after Yakov Borisovich Zeldovich, Amable Liñán and John W. Dold. The model includes a chain-branching and a chain-breaking (or radical recombination) reaction. The model was first introduced by Zeldovich in 1948, later analysed by Liñán using activation energy asymptotics in 1971 and later refined by John W. Dold in the 2000s. The ZLD mechanism mechanism reads as
where is the fuel, is an intermediate radical, is the third body and is the product. This mechanism exhibits a linear or first-order recombination. The model originally studied before Dold's refinement pertains to a quadratic or second-order recombination and is referred to as Zeldovich–Liñán model. The ZL mechanism reads as
In both models, the first reaction is the chain-branching reaction (it produces two radicals by consuming one radical), which is considered to be auto-catalytic (consumes no heat and releases no heat), with very large activation energy and the second reaction is the chain-breaking (or radical-recombination) reaction (it consumes radicals), where all of the heat in the combustion is released, with almost negligible activation energy. Therefore, the rate constants are written as
where and are the pre-exponential factors, is the activation energy for chain-branching reaction which is much larger than the thermal energy and is the temperature.
