A hybrid method for the numerical prediction of enthalpy transport in fluid flow

A hybrid method (HM) is proposed for the prediction of convective enthalpy transport and the boiling boundary location. The momentum equation is solved with the SIMPLE procedure, while the energy equation is solved with the Method of Characteristics (MOC) and with the application of the Lagrange interpolation polynomial (LIP). The MOC method is applied on an equidistant grid. The initial values at the starting points of characteristic paths are calculated with the LIP. The accuracy of the method is demonstrated on tests of the transient boiling boundary prediction and the well known problem of a propagating discontinuity. The dependence of the hybrid method on the spatial integration step size and the degree of the LIP is analyzed. The LIP of the third degree is recommended, by which practically exact solutions with acceptable number of nodes are obtained. (C) 2000 Elsevier Science Ltd.