A one-dimensional (1-D) model of the RAMAC utilizing subsonic combustion followed by thermal choking, based on both quasi steady and unsteady assumptions, and including real-gas effects is presented. This 1-D model that includes projectile acceleration effects has been further extended to include real-gas equations of state (EoS) in order to account for the compressibility effects of the combustion products. The net thrust is determined after solving a set of 1-D conservation equations by means of an iterative procedure. Computing the compressibility factor for a given equation of state is the basis for incorporating the real gas corrections. Numerous equations of state have been developed based on generalized empirical and theoretical considerations. Several formulations were incorporated in the computer code TARAM. Yet, the accurate choice of the EoS is a key factor for the reliability of this code. The objective of this paper is to provide a review of the best available formulations in order to improve the unsteady 1-D model and make the TARAM code a useful tool to predict the performance of the RAMAC in the sub-detonative velocity regime, without having to resort to more complicated 2-D or 3-D computational schemes. The calculations are validated against experimental data from 38-mm and 90-mm bore RAMAC facilities.
展开▼
