The article describes the prospects for experimental research of liquid-vapor jet devices with adaptable geometry of the flow part of the primary flow nozzle. To formulate the research objectives, a critical analysis of state-of-the-art studies was conducted among native and foreign scientists studying two-phase jet devices. As a result, of the literature survey, we saw that the working process of the two-phase jet devices, which include liquid-vapor jet devices, is quite complicated to study. So, the achieved results of theoretical studies require clarification and the conduction of additional experimental studies. The article provides a description and experimental research method on the liquid-vapor jet devices with a replaceable diffuser part of the primary flow nozzle. The program and the method contain the range of changing operational parameters while conducting experimental studies. The functional scheme of the experimental scheme and the devices to control and measure pressure in the critical points of the scheme are proposed.