Numerical Comparison Study on the Effects of Detonation Wave Collisions and Reflections

ABSTRACT

Continuous detonation engines such as rotating detonation combustors (RDC), shuttling transverse combustors (STC) etc exhibit quasi-steady wave modes. While there have been studies regarding the parametric dependencies of such wave modes, their relative influence on combustion performance is not well understood. Notably, the wave reflection phenomena observed in shuttling transverse combustors has been proposed to support detonations under lean or low plenum pressure conditions. Hence, it is of interest to study the mechanisms underlying the engine performance corresponding to each wave mode, with the aim to potentially aid in detonation engine design and operations. This numerical study compares the injector recovery, peak pressures and combustion efficiencies associated with these wave modes for a 2D RDC and STC geometry with plenum.

Development of Thermal Soaring Simulation Model and Control Algorithm for Autonomous Thermal Soaring

ABSTRACT

When the Sun heats the Earth’s surface unevenly, rising column of hot air, known as thermals are formed. These are commonly used by birds and manned gliders to remain airborne for longer periods whilst saving energy, thus increasing their flying range and endurance. This energy harvesting method is known as thermal soaring. UAVs could also utilize these thermals to improve their performance, by means of autonomous thermal soaring. A thermal soaring stimulation model was developed using Python, to simulate UAV behavior and interaction with a thermal. This model is then used to develop an autonomous thermal soaring control algorithm for UAV. This control algorithm consist of search trajectory, thermal detection and thermal center estimation for maximizing altitude gain.