Conchas-spray: A computer code for reactive flows with fuel sprays

This report describes the CONCHAS-SPRAY computer code, which solves the equations of transient multicomponent chemically reactive fluid dynamics, together with those for the dynamics of an evaporating liquid spray. The code is of quite general applicability, but has been developed with applications to internal combustion engines specifically in mind. The formulation is spatially two-dimensional, and encompasses both planar and axisymmetric geometries. In the latter case, the flow is permitted to swirl about the axis of symmetry. CONCHAS-SPRAY is a time-marching finite-difference code that uses a partially implicit numerical scheme. Spatial differences are formed with respect to a generalized two-dimensional mesh of arbitrary quadrilaterals whose corner locations are specified functions of time. This feature allows a Lagrangian, Eulerian, or mixed description, and is particularly useful for representing curved or moving boundary surfaces. Arbitrary numbers of species and chemical reactions are allowed. The latter are subdivided into kinetic and equilibrium reactions, which are treated by different algorithms. A turbulent law-of-the-wall boundary layer option is provided. The governing equations, numerical scheme, and code structure are described in detail, and a FORTRAN listing of the code is given in an appendix.