Numerical Investigation on Combustion and Heating Characteristics of Metal Fiber Burner

Abstract

A metal fiber burner is proposed for structural thermal tests for the test model of hypersonic vehicles. In order to guide the design of the burner, we conduct Fluent simulations on a cylindrical metal fiber burner with a properly selected thermal diffusion model, a heat transfer model between the gas and solid phase, a radiation model with a metal porous media, and a gaseous combustion chemistry mechanism. After validating the simulation, the combustion and heating characteristics of the burner were further analyzed. The results show that under the condition of no specimen, when the firing rate increases from 120 kW/m2 to 240 KW/m2, the maximum gas temperature and the downstream gas temperature of the metal fiber increase by 6.21% and 8.55%, respectively, the outer surface temperature of the metal fiber increases by 6.42%, and the stable gas temperature downstream of the metal fiber reaches the maximum value at an equivalence ratio of 1. After the specimen is added, the internal and downstream gas temperatures of the metal fiber are significantly reduced, while the upstream gas and outer surface temperatures of the metal fiber show no significant changes. When the specimen diameter changes from 139mm to 98mm, the gas temperature and fiber surface temperature change is small, while the surface heat flux of the specimen significantly increases from 12.7 KW to 22.7 KW. It can be seen that when designing the test parameters, the surface heat flux of the specimen can be adjusted by adjusting the distance between the combustion surface and the specimen.

Keywords

• structural thermal test
• metal fiber
• porous medium
• combustion and heating characteristics
• numerical simulation