can anyone say what does this syntax is?

[9iEAC542]

defineTypeNameAndDebug(SpalartAllmaras, 0);
addToRunTimeSelectionTable(turbulenceModel, SpalartAllmaras, dictionary);

// * * * * * * * * * * * * Private Member Functions * * * * * * * * * * * * //

tmp<volScalarField> SpalartAllmaras::chi() const
{
return rho_*nuTilda_/mu();
}


tmp<volScalarField> SpalartAllmaras::fv1(const volScalarField& chi) const
{
volScalarField chi3 = pow3(chi);
return chi3/(chi3 + pow3(Cv1));
}




^{what does this "tmp<volScalarField>" refers}

[kbw]

tmp is a template class, specialised by class volScalarField.

You should have access to the definition of tmp. We can only guess what it might do.