The linear counterpart of the rotational switched reluctance drive is receiving increasing attention from academic and industrial societies. The special characteristics of this driving technology, that normally works in a highly magnetic saturation regimen, make the development of efficient design methodologies more difficult. This paper proposes a new numerical model of a Linear Switched Reluctance Actuator based on the flux tube method. For validation purposes, simulation results obtained from the application of presented model are compared with the ones obtained from the application of a commercial finite element tool. The modulation technique proposed here makes possible, with minimal computational effort, the evaluation of the impact in actuator behaviour caused by the changes on the magnetic circuit geometries.