Evaluation of Thrust Performance in Scramjet Engines with Measured Internal Drag

Abstract

A one-dimensional theoretical method for an evaluation of the net thrust of a scramjet engine is presented. To calculate the thrust performance of the engine analytically, an efficiency characterizing compression process, such as recovery factor in total pressure or kinetic energy efficiency etc., is necessary. In the previous theoretical method, this efficiency was roughly assumed. Although the effect of aerodynamic parameters and configuration parameters on the thrust can be investigated with this rough assumption, the net thrust evaluated with this method was not enough accurate to be compared with the measured thrust in experiments. The total pressure loss is chosen as the efficiency in this paper. This total pressure loss is evaluated from the engine internal drag with the wind tunnel experiment, which is due to irreversible process through the engines. The theoretical maximum thrust of the engines can be calculated with this new method.