Consistent initial conditions for unstructured higher index DAES: a computational study

Differential algebraic equations (DAEs) are implicit systems of ordinary differential equations, F (x′, x, t) = 0, for which the Jacobian Fx′ is always singular. DAEs arise in many applications. Significant progress has been made in developing numerical methods for solving DAEs. Determination of consistent initial conditions remains a difficult problem especially for large higher index DAEs. This paper looks at one approach for computing consistent initial conditions for these systems. The focus is on initializing higher index DAE integrators but the observations are relevant to the general problem of initialization of DAE integrators.