Gas-Dynamic Model of the Expansion of a Pulse Jet of Supercritical Carbon Dioxide: The Strategy of the Experiment

An experimental strategy for determining the coil–globule transition parameters of a polymer chain in supercritical carbon dioxide has been developed on the basis of a gas-dynamic model of the expansion of a pulse jet of a van der Waals gas [1]. Taking into account the behavior of CO2 in the near-critical region and isentropic conditions of the jet expansion process, starting conditions that arise in the nozzle and correspond to the proposed model are determined. The design of the experiment (geometrical and size parameters of the key components of the equipment, pulse valve duration, etc.) is developed. Possible options for carrying out the experiment and processing the experimental data are discussed. Calculation procedures for the case corresponding to the experimental conditions described in [2, 3] are given as an example.