Analysis of the dehydration performance in a two-phase variable-section gas wave oscillation tube

•A variable-section TPGWOT which can improve dehydration performance is proposed.•Coupling the CPA equation of state with the non-equilibrium phase transition model.•The wave systems in the gas wave oscillation tube are optimized.•The gas temperature drop and the dehydration rate are improved. The two-phase gas wave oscillation tube (TPGWOT) is subjected to several problems in the application of moisture-containing gas dehydration (e.g., less accurate prediction of the results of phase transition in the tube, and strong interference effect of reverse compression waves in the tube). The predicted phase transition results approach the experimental values by coupling the CPA real gas model and the non-equilibrium phase transition model. The performance of the proposed variable-section TPGWOT is investigated using numerical and experimental methods, and the following results are achieved. The variable-section structure is capable of optimizing the wave system in the tube, as manifested by the ability to strengthen the reflected expansion wave and weaken the reverse compression waves. As a result, the maximum condensation rate of condensate droplets is increased by 2 % to 5 %, and the proportion of evaporation capacity of condensate droplets is reduced by 3 % to 7 %. The variable-section structure is capable of enhancing the performance of the GWOTs, as manifested by the ability to improve the gas temperature drop (ΔT) of nearly 20 % and increase the dehydration rate by 2.6 % to 5 %. This study is no longer limited to optimizing the wave system in the tube by changing the ports at both ends of TPGWOTs, and it provides a favorable reference for other wave rotor application research.