Method for determining gasoline surrogate component proportions and development of reduced chemical kinetics model of the determined surrogate fuel

Abstract

Response surface method is used to build models for predicting an octane number and determining the component proportions of a gasoline surrogate fuel. The fuel is synthesized using toluene, iso-octane, and n-heptane and is referred to as toluene reference fuel. The built models include second-order model and third-order model. Both models can excellently predict the octane number of the toluene reference fuel with known component proportions. Moreover, the third-order model is more accurate than second-order model in determining the component proportions of the toluene reference fuel, and the relative error is less than 8%. Therefore, the third-order model can accurately predict the octane number and determine the component proportions of the toluene reference fuel. Moreover, a new reduced mechanism of the toluene reference fuel is proposed and validated by using shock tube ignition delay and in-cylinder pressure in a homogeneous charge compression ignition engine. The toluene reference fuel mechanism coupled with third-order model is used to simulate the ignition delay of American gasoline (RD387) and the homogeneous charge compression ignition combustion behaviors of European gasoline (ULG95). Both cases are simulated thoroughly.

Modelling liquid film in modern GDI engines and the impact on particulate matter emissions – Part 1

“…21 Although the commercial gasoline fuels are a blend of many different hydrocarbons, 38 engine CFD simulations have been routinely using mono-component fuel models like N-Heptane or Isooctane 36,[39][40][41] to simplify the analysis and/or reduce the otherwise large computational burden. More complex fuel models have been adopted such as the Primary Reference Fuel (PRF), a mixture of N-Heptane and Iso-octane, and the Toluene Reference Fuel (TRF), a mixture of N-Heptane, Iso-octane and Toluene 33,42 In some cases, 43 fuel models are used where specific properties are optimised to represent a TRF blend, 44,45 but with the added benefit of being treated as a single-component model within the CFD solver. 46 Whilst PRF and TRF fuel models may be suitable for combustion modelling (appropriately reflecting Lower Heating Value, aromatic content and RON of commercial gasolines), along with single-component models they lack accuracy in replicating the complex thermo-physical behaviour which characterises the spray and mixture preparation stages of the engine cycle.…”