A CLASS OF HALF-EXPLICIT RUNGE-KUTTA METHODS FOR DIFFERENTIAL-ALGEBRAIC SYSTEMS OF INDEX-3

This paper introduces half-explicit Runge-Kutta methods for the soluti on of differential-algebraic systems of index 3. Half-explicit methods only treat the algebraic variables implicitly, hence have computation al advantages compared to fully implicit schemes. For a class of parti tioned methods, order conditions are derived and convergence is proved . Particular methods up to order 3 are given and a numerical experimen t, illustrating the theoretical results, is included.