Study On Swirl Flow Field Characteristics Of Stamping Engine

Solid fuel ramjet have several advantages including safety, simple structure and large specific impulse, which has been widely used in missiles, aircraft fields, etc. However, the SFRJ combustion organization turns out to be difficult, which also has low combustion rate and efficiency. In this paper, numerical simulation and experimental validation have been used to study swirl cold flow field characteristics, analyze the impact of the swirler on the ramjet flow structure and explore the role of swirl on combustion and overall engine performance.First of all, this paper improves the original design of swirler, determine the design size through engine size and structure of ignition, use NACA airfoil vane swirler design reference to reduce the total pressure loss and strengthen rotation. According to the results of the simulation data and formulas, determines the blade angle of attack, camber and number of leaves. In order to meet the requirements of the experimental conditions, the original size is reduced and the positioning of the blade and processing methods are determined.Then, take simulation of the swirler and the engine structure. Analysis the combined effects on the swirl number with four different angles of attack and three kinds of camber by using RNG turbulence model in fluent and periodic grid, and gain the swirler cold flow field structure, the swirl number, velocity field of the front portion combustion and swirler in twelve conditions. Studys the pressure, temperature, velocity distribution in inlet, the factors which affect swirl number, the distributions of radial, circumferential, axial velocity and the attenuation of swirl number.And then, take measurement of rotational and irrotational flow in six conditions with particle image velocimetry(PIV). Use MgO as tracer particles get the combustor flow field pattern in single-frame shooting mainly. Use dynamic studio software adaptive cross-correlation algorithm to process the measurement image, filter nonlinear value by simulation results and take averaged statistics, eventually, obtain the axial velocity profile and cross-sectional velocity of outflows field.Finally, calculate the experimental swirl number of NACA vane swirler. Study the effect of swirl on the performance of the ramjet by comparing no spin and spin velocity field and swirler field of different inlet conditions. The study results indicated that the NACA vane swirler can meet the design requirements.