Assessment of Combustion Efficiency in a Scramjet Combustor through Wall Pressure and Calorimetry Measurements

This thesis presents both experimental and numerical investigations into the process of supersonic combustion within a scramjet engine. The study employs four different fuel injection methods. The main objective of this research was to assess the efficiency of each injection approach using a one-dimensional model of the scramjet.

The experimental setup includes a scramjet combustor with a flame-holding cavity, where primary fuel ports are positioned upstream of the cavity. Water channels are used to cool the upper and lower sections of the combustor. Flow rates and water temperatures were monitored to estimate potential heat losses. Through pressure measurements taken along the chamber, a pressure profile was generated. This profile was then used as an input for a 1D model of the scramjet combustor, along with heat loss estimates, to simulate the process and determine the combustion efficiency of the injection methods.

The 1-D model of the scramjet combustor used in this study is based on the conservation equations of mass, energy, and momentum, as well as the ideal gas law and the conservation of species. The model was able to predict the combustion efficiency that may be used to optimize the design of the injectors and compare the performance of the tandem configuration with that of a single injector configuration. Using this model, detailed information about the temperature, pressure, and species concentrations within the combustor can be obtained, making it a useful tool for designing scramjet engines and optimizing their performance.