Supersonic engine intakes

The behaviour of oblique shock waves is important in the design of supersonic engine intakes when the Mach number is greater than 2.

 Credit: Holger Babinsky

This Schlieren visualisation shows the reflection of a supersonic oblique shock wave at M=2.5, where the incident shock wave was generated with an 8° wedge. The resulting interaction of the shock wave with the turbulent boundary layer growing along the plate produces a separation bubble.

 Credit: Holger Babinsky

The left-hand image shows a plan view of the surface streamlines, produced with oil-flow visualisation, underneath the above supersonic oblique shock reflection, while the right-hand image depicts the surface pressure field (obtained from pressure sensitive paint) superposed on the streamline pattern.

Active galactic nuclei as drivers of large-scale outflows

 Credit: Tiago Costa and Debora Sijacki

Simulation of a point explosion in a dense, spherical, self-gravitating cloud with the moving mesh code Arepo (highest density regions are shown in red). Point explosion generates a central cavity and a dense, highly compressed shell of gas which propagates outwards with time in the energy-conserving fashion, as shown in the series of panels. At later times the shell becomes Rayleigh Taylor unstable which leads to the development of the characteristic "mushroom-like" features and eventual mixing of the shell with the surrounding medium. For further details see Costa, Sijacki, Haehnelt, 2014, MNRAS, 444, 2355.