@article{LangdonArmsGschwendtnerNeumaier2019, author = {Langdon-Arms, Samuel and Gschwendtner, Michael and Neumaier, Martin}, title = {Rayleigh-Taylor instability in oscillating liquid pistons}, series = {Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science}, volume = {233}, journal = {Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science}, number = {4}, pages = {1236 -- 1245}, year = {2019}, abstract = {In this study, an experimental apparatus is used to excite four U-tube-shaped liquid pistons connected in series, and to study their behaviour. Some of the gas spaces are heated to induce piston oscillations; in others, gas expansion is utilised to produce a refrigeration effect. It was discovered that the liquid piston surface would become unstable and turbulent at relatively low gas charge pressures (2 bar-3 bar). Cylindrical polyethylene floats were employed at each piston surface in order to reduce the area of the free surface of each piston and allow experiments to be conducted over a wide range of operating conditions. Experiments were carried out using gas charge pressures in the range of 1 bar-6 bar. The resulting liquid piston oscillations were measured and analysed to assess the impact of any developing piston instability. Evidence of a liquid piston acceleration limit, likely resulting from the Rayleigh-Taylor instability phenomenon, is consistently observed during the experiments. The use of submerged polyethylene piston floats is found to increase the surface stability and enable maximum accelerations of 25 ms-2 to 30 ms-2.}, language = {en} }