Journal of Applied Mechanical Engineering

A perspective of shock waves: with examples in aerodynamics and granular flows

2^nd International Conference on Fluid Dynamics & Aerodynamics

October 19-20, 2017 | Rome, Italy

Xinjun Cui

Sheffield Hallam University, UK

Posters & Accepted Abstracts: J Appl Mech Eng

Abstract:

Shock waves are a well-known phenomenon in aerodynamics, which can be observed when a supersonic flow moves around obstacles. However, the term of �??shock�?� can be applied to many other areas when similar phenomena take place, for example, during gravity-driven granular flows past obstacles. Though the concept of granular shock waves was suggested by Savage a few decades ago, the study of the granular shock phenomena only started to capture more interest in the past decade when Gray et. al. investigated a series of shock waves using a shallow-water type model. Gray & Cui made a systematic study to the granular shock wave theory, which was shown bearing much analogies, but also with distinctive characteristics, to the classical gas dynamic shock waves. With a fairly simple laboratory experiment they successfully generated a strong oblique shock wave that would be normally much more difficult to achieve in gas-dynamical circumstances. Another analogous study of the shock waves was conducted relatively recent on the flow past circular cylinder problem under the granular flow conditions by Cui and Gray, and by Sinclair & Cui for the aerodynamical conditions. Undoubtedly, there are clear similarities and differences in terms of the nature of the shock waves when aerodynamics and granular flows are concerned. This talk intends to depict some basic pictures about different shock wave phenomena from theoretical, computational and practical perspectives, where examples of oblique, bow shock, weak and strong shock waves will be addressed.