Fuel surrogates are mixtures of one or more simple fuels that are designed to emulate either the physical properties (

vapor pressure Vapor pressure or equilibrium vapor pressure is the pressure exerted by a vapor in thermodynamic equilibrium with its condensed phases (solid or liquid) at a given temperature in a closed system. The equilibrium vapor pressure is an indicat ...

) or combustion properties (

laminar flame speed Laminar flame speed is an intrinsic characteristic of premixed combustible mixtures. It is the speed at which an un-stretched laminar flame will propagate through a quiescent mixture of unburned reactants. Laminar flame speed is given the symbo ...

heating value The heating value (or energy value or calorific value) of a substance, usually a fuel or food (see food energy), is the amount of heat released during the combustion of a specified amount of it. The ''calorific value'' is the total energy release ...

, etc.) of a more complex fuel. While surrogate mixtures can demonstrate more than one characteristic of the desired fuel, more often than not different components are required in order to emulate the wide variety of properties that are of interest to researchers.

Jet fuel Jet fuel or aviation turbine fuel (ATF, also abbreviated avtur) is a type of aviation fuel designed for use in aircraft powered by Gas turbine, gas-turbine engines. It is colorless to straw-colored in appearance. The most commonly used fuels for ...

is an example of a fuel requiring a surrogate for experimental research and numerical modelling due to its complexity and high content variability from one batch to the next. Neat hydrocarbon jet fuel surrogate components include

decane Decane is an alkane hydrocarbon with the chemical formula C10H22. Although 75 structural isomers are possible for decane, the term usually refers to the normal-decane ("''n''-decane"), with the formula CH3(CH2)8CH3. All isomers, however, exhi ...

dodecane Dodecane (also known as dihexyl, bihexyl, adakane 12, or duodecane) is an oily liquid ''n''-alkane hydrocarbon with the chemical formula C12H26 (which has 355 isomers). It is used as a solvent, distillation chaser, and scintillator component. It ...

methylcyclohexane Methylcyclohexane (cyclohexylmethane) is an organic compound with the molecular formula is CH3C6H11. Classified as saturated hydrocarbon, it is a colourless liquid with a faint odor. Methylcyclohexane is used as a solvent. It is mainly converted ...

, and

toluene Toluene (), also known as toluol (), is a substituted aromatic hydrocarbon with the chemical formula , often abbreviated as , where Ph stands for the phenyl group. It is a colorless, water Water is an inorganic compound with the c ...

. Gasoline surrogate components include

n-heptane Heptane or ''n''-heptane is the straight-chain alkane with the chemical formula H3C(CH2)5CH3 or C7H16. When used as a test fuel component in anti-knock test engines, a 100% heptane fuel is the zero point of the octane rating scale (the 100 poi ...

and

iso-octane 2,2,4-Trimethylpentane, also known as isooctane or iso-octane, is an organic compound with the formula (CH3)3CCH2CH(CH3)2. It is one of several isomers of octane (C8H18). This particular isomer is the standard 100 point on the octane rating scale ...

Hexadecane Hexadecane (also called cetane) is an alkane hydrocarbon with the chemical formula C16H34. Hexadecane consists of a chain of 16 carbon atoms, with three hydrogen atoms bonded to the two end carbon atoms, and two hydrogens bonded to each of the 1 ...

is a diesel surrogate component. Biodiesel surrogate components include

methyl butyrate Methyl butyrate, also known under the systematic name methyl butanoate, is the methyl ester of butyric acid. Like most esters, it has a fruity odor, in this case resembling apples or pineapples. At room temperature, it is a colorless liquid with ...

and methyl decanoate.

References

{{Reflist Fuels