Numerical and experimental study of filling a vessel with a component of gas mixture

Abstract

The subject of the research is mathematical models of a gas-dynamic non-stationary process of filling a vessel with a component of a gas mixture. The aim of the study is the scientific and experimental substantiation of the choice of a model of filling a vessel with a component of a gas mixture with a given accuracy. The objectives of the study are to conduct full-scale experiments on filling the vessel with gas for further verification of the gas mixture generation control system, as well as in the development of adequate mathematical models of gas-dynamic flow, the analysis of simulation results, and the use of verified results in the system of automated generation of a gas mixture of a given accuracy by assessing the mass of its components depending on the filling parameters. The tasks are solved by studying the results of numerical modeling of the process and full-scale experiments. The following results are obtained. A series of full-scale experiments on filling a vessel with high-frequency monitoring of the pressure and temperature of the gas being filled was carried out. Significant factors were analyzed. The use of SAS SST turbulence models was substantiated. Models of the gas-dynamic unsteady process of filling the vessel with a component of the gas mixture for various values of the mass flow rate had been built. All the simulations were carried out using the ANSYS CFX software package. The influence of considering a heat exchange with the vessel walls on the studied parameters of the mixture is determined, namely: pressure, gas temperature averaged over the volume, gas temperature in a control point, mass of the component of a gas mixture. It was found that the deviation of the calculated data when using a model with an adiabatic condition on the wall compared to a model with a constant temperature regime is: for pressure – no more than 5 %, for averaged temperature – 6 %, for the temperature at the monitor point – 9 %, for mass – 1.5 %. The discrepancy between the simulation results and the full-scale experiment does not exceed 12 % in pressure and temperature at the monitor point, as well as 4 % in the mass of the component. By the experimentally determined accuracy parameter of the gas mixture (the mass of the mixture component in particular), the numerical models had been corrected to provide the mass value error of no more than 0.5 %.

Keywords

• математична модель газодинамічного процесу
• параметри наповнення резервуару
• числове моделювання
• точність газової суміші