Ramjet Adjustable Nozzle Flow Field Numerical Simulation

Using regulated nozzle can improve the Ramjets' performance and missiles' maneuverability . The regulated nozzle has many moving parts in work. At present , many problems , such as what about of its flow field configuration , the distributed characteristic of its flow parameters, pressure load of its inside are waiting for resolving . So, a detailed numerical simulation of flow field in regulated nozzle using two-stage throats need be conducted.The contents of this paper include:1. Based on the structure specialty and flow field characteristic of this regulated nozzle, the mathematical models are selected as RNG к - ε turbulence model and Navier-Stokes equations.2. Using CFD software - FLUENT, many flow states were been simulated. These states are the influence of nozzle structure with the flow, the distributing characteristic of inside flow , the influence of cold gas flow and outside flow with the work of the nozzle, the change of inside pressure load when the nozzle regulates.3. The calculated results of cold nozzle flow are in agreement with some cold test one. Through calculation, the parameter distributions of regulated nozzle flows were obtained . They state that the design of the regulated nozzle is reasonable, and its velocity loss at discharge section is less than 2.3% comparison with no regulated nozzle.