An algorithm has been proposed for the march calculation of supersonic flow around the launch vehicle with a ring wing, which is equipped with a ramjet engine. The special feature of the developed algorithm is the introduction of two sub-regions in the computational domain where the ring wing is placed on the body of the launch vehicle. The computational domain is divided into two sub-regions when the march section hits the leading edge of the ring wing – a lower sub-region, which is located between the surface of the body of the launch vehicle and the lower surface of the ring wing, and an upper sub-region, which is placed between the upper on the surface of the ring wing and the front of the head shock wave. When the march section is placed on the rear edge of the ring wing, the lower and upper sub-regions merge with what appears to be one computational domain. Based on an algorithm from a previously created program for the flow around launch vehicles, software was designed for the operational numerical calculation of the supersonic flow around launch vehicles with round or elliptical wings that hug the rocket body. The created software allows for a significant reduction in computational time with an accuracy acceptable for design.

            The results of numerical calculations of the supersonic flow are presented in the form of isoline fields of gas-dynamic parameters in the flow field and pressure distributions on the surfaces of the launch vehicle body and the ring wing for a specific form of a launch vehicle with a ring wing. It is shown that the use of a ring wing leads to a wave nature of pressure distribution in the area between the surface of the body of the launch vehicle and the lower surface of the ring wing. As the angle of attack increases, the pressure in the leeward part of this region exceeds the pressure in the windward part of the field. The distributions of the total aerodynamic characteristics of forces and moments acting on the considered launch vehicle configuration are given.