Recent advances in theory, simulations, and experiments on multiphase flows

Multiphase flows, which are ubiquitous in nature but usually involve complex physical processes, have important applications in many areas of aeronautics, astronautics, the oil and gas industry, combustion, and pharmaceuticals, among others. However, the study of multiphase flows is usually more difficult than its single-phase counterpart due to the presence of complex fluid-fluid and fluid-solid interfaces and the wide range of scales from the microscopic level to macroscopic level. In recent years, new numerical methodologies, experimental techniques, and theoretical analysis tools for studying and analyzing complex multiphase flow problems have advanced significantly. Therefore, this special topic is devoted to the recent advances and developments of these tools in the study of multiphase flows. Thirteen papers have been published and they cover a variety of essential topics, which include multiphase flows with large density ratios and multi-physics fields, particle-laden turbulent flows, boiling flows with phase change, three-phase flows for enhanced oil recovery, and coaxial jets with heat transfer.