A semi-implicit space-time CE-SE method to improve mass conservation through tapered ducts in internal combustion engines

In this work, we present a semi-implicit method based on the CE-SE numerical scheme (space time conservation-element and solution-element). In particular, we apply this method to a hyperbolic system that models the dynamics of an unsteady flow along a tapered duct with friction and heat transfer. Conditions on the scheme in order to get real numerical solutions are given. The improvement that offers the semi-implicit method versus the scheme CE-SE is compared by means of numerical simulations based on the property of the mass conservation.