SUMMARYThis paper presents an improvement in the conservation element-solution element (CE-SE) scheme for calculating one-dimensional flow through tapered ducts. This new CE-SE scheme has been validated against experiments in tapered ducts with non-steady flow using pressure impulses. This validation analyses scheme's ability to reproduce instantaneous pressure in time and frequency domains, mass conservation when the section of the duct changes (which was the main drawback of the original CE-SE scheme) and finally computational time. In order to quantify the improvement of the scheme, the calculations have been compared with experimental data and with the results provided by other schemes, such as the original CE-SE or total variation diminishing schemes. This comparison shows important improvements in mass conservation in relation to the original CE-SE and not significant penalties in computational time.