Investigation Of The Response Process Of Variable Flow Ducted Rocket

Demonds for high performance propulsion system for the next generation missile have greatly promoted the research and development of Variable Flow Ducted Rocket (VFDR). Alough considerable progress in this field has been seen, still many issues, especially the response characteristics of VFDR, remained for us to conduct further investigation. Approaches of theoretical analysis and numerical simulation were both applied to study the response characteristics of VFDR in this dissertation.Physical mechanisms of anti-regulation phenomenon in the regulation process of VFDR have been discovered through theoretical analysis. A theory of anti-regulation was established, and it theoretically answered the questions of why does anti-regulation happen, when does it happen, when will it stop and how is it influenced by some given parameters. The concept of Critical Change Rate of gas generator Throat Area (CCRTA) were initiated and defined, calculation methods of CCRTA, anti-regulation duration and anti-regulation extent were also provided. The anti-regulation theory was validated by theoretical calculation results and VFDR experiment data.Based on ALE depicted N-S equations as well as dynamic mesh method, an unsteady numerical simulation method for the unsteady working process of VFDR has been established. The correctness of this simulation method was verified by analytical solution of one dimensional expansion wave propagation problem and VFDR experiment data.Numerical investigation of the unsteady working process of mechanical valve style VFDR was conducted, the variation of flow field inside the VFDR and the response characteristics were analyzed. An evaluation system of the response characteristics has been established. The influences of valve velocity, pressure exponent, free volume etc. were calculated and analyzed. The anti-regulation theory was validated again.Numerical simulation method of gas throat style VFDR was established and validated by relevant experiment data. Steady and Unsteady regulation property of gas throat style VFDR was studied using this method. The results demonstrated the feasibility of gas throat style VFDR. The influences of the secondary flow - main flow rate and secondary flow inject angle were investigated, which indicated that the anti-regulation theory established in this dissertation is also suitable for gas throat style VFDR.