The axially symmetric, swirl-free gas dynamics and interlinked motion of a cork stopper provoked by the opening of a champagne bottle are modelled rigorously and studied numerically. The experimental study by Liger-Belair et al. (Science Advances, 5(9), 2019) animated the present investigation. Inspection analysis justifies the inviscid treatment of the expanding jet of air enriched with dissolved carbonic acid gas initially pressurised in the bottle. Solving of the resulting Euler equations is facilitated by the open-source software Clawpack. Specific enhancements allow for resolving of the emerging supersonic pockets, associated with surprisingly complex shock structures, as well as the gas–stopper interaction with due accuracy. Our experimental effort provided modelling of the frictional behaviour, constitutive law and reversible (de-)compression of the cork material. Initially, the gas expands inside the bottleneck yet sealed by the stopper, and is hence accelerated by the gas but decelerated by dry sliding friction. Once the stopper has passed the bottle opening, the jet rapidly assumes locally supersonic speed, where a complex shock pattern is detected. Special attention is paid to the formation and dissolution of one or even two Mach discs between the opening and the released stopper. This simulated dynamics is found to be in fairly good agreement with recent experimental findings. It also provides a first insight into the generation of the typical popping sound.

Over the years, many facilities have been developed to study turbulent flow in the laboratory. Homogeneous isotropic turbulence (HIT) with zero mean flow provides a unique environment for investigating fundamental aspects and specific applications of turbulent flow. We provide an extensive overview of laboratory facilities that generate incompressible zero-mean-flow HIT using different types of actuators and configurations. Reviewed facilities cover a variety of geometries and sizes, as well as forcing style (e.g. symmetric versus asymmetric and unsteady versus steady). We divide facilities into four categories, highlighting links between their geometries and the statistics of the flows they generate. We then compare published data to uncover similarities and differences among various turbulence-generation mechanisms. We also compare the decay of turbulence in zero-mean-flow facilities with that observed in wind and water tunnels, and we analyse the connections between flow characteristics and physical aspects of the facilities. Our results emphasize the importance of considering facility geometry and size together with the strength and type of actuators when studying zero-mean-flow HIT. Overall, we provide insight into how to optimally design and build laboratory facilities that generate zero-mean-flow HIT.