Summary of Recent Research on Detonation Wave Engines at UTA
A survey of recent research at UTA on detonation waves related to propulsion is presented in this paper. A brief historical review of the early pulse detonation engine (PDE) research at UTA is provided to lay the background for the development of a large-scale PDE Ground Demonstrator. Also current activities related to the development of rotating detonation wave engines (RDE) are reviewed. System integration studies for both PDE- and RDE-based propulsion systems are summarized, followed by a brief description of two programs focusing on application of detonation waves to hypersonic flow simulation and power generation.
Influence of Gaseous Hydrogen Addition on Initiation of Rotating Detonation in Liquid Fuel–Air Mixtures
Hydrogen is the most common molecule in the universe. It is an excellent fuel for thermal engines: piston, turbojet, rocket, and, going forward, in thermonuclear power plants. Hydrogen is currently used across a range of industrial applications including propulsion systems, e.g., cars and rockets. One obstacle to expanding hydrogen use, especially in the transportation sector, is its low density. This paper explores hydrogen as an addition to liquid fuel in the detonation chamber to generate thermal energy for potential use in transportation and generation of electrical energy. Experiments with liquid kerosene, hexane, and ethanol with the addition of gaseous hydrogen were conducted in a modern rotating detonation chamber. Detonation combustion delivers greater thermal efficiency and reduced NOx emission. Since detonation propagates about three orders of magnitude faster than deflagration, the injection, evaporation, and mixing with air must be almost instantaneous. Hydrogen addition helps initiate the detonation process and sustain continuous work of the chamber. The presented work proves that the addition of gaseous hydrogen to a liquid fuel–air mixture is well suited to the rotating detonation process, making combustion more effective and environmentally friendly.
Impulse of a Single-Pulse Detonation Tube
This report describes experimental and numerical investigations on pulse detonation tubes carried out in the Explosion Dynamics Laboratory at Caltech during 1999-2002. The goal of this work was to develop a database on impulse measurements using direct ballistic measurement of impulse; and to develop a model based on simple gas dynamic principles that could be used to predict impulse for a wide range of fuels and initial conditions. At the time we started this work, there was a great deal of conflicting information regarding the values of impulse that could be obtained. Our goal was to clarify this situation and to develop a better understanding of the factors that controlled impulse generation in a pulse detonation tube - the simplest version of a pulse detonation engine. Since we began this project, many groups from throughout the world have made impulse models, carried out new numerical studies, and made direct experimental measurements of impulse. The work of these researchers has been invaluable to us as we refined and tested our ideas against their data and ours. We would like to acknowledge discussions with Fred Schauer (AFRL, USA), Chris Brophy (NPS,USA), K. Kailasanath (NRL, USA), R. Santoro (PSU, USA), Andrew Higgins (McGill University), Paul Harris (DREV, Canada), and E. Daniau (ENSMA - France). In particular, we thank Fred Schauer for generously sharing his data with us. 
 
We initially began preparing this report in 2000 and it went through a number of revisions with portions being presented at the Joint Propulsion Conference in the summer of 2001. Subsequently, the material underwent further revision and additions in preparation for journal publication and the orginal report was significantly out of date. We have chosen to replace the original text with preprints of our journal articles and retained the appendices to the original report. The material in Parts II and III consist of preprints of revised versions (accepted for publications) of two papers submitted to the Journal of Propulsion and Power in the winter of 2001-2002. The Appendices contain additional details about the modeling, details on the experimental setup, tabulated data from the experiments, and tabulated results of model computations.