Numerical study on startup behaviors of dense powder conveying in powder fueled ramjets using modified TFM incorporated with μ(I) rheology theory

In-depth understandings of propellant conveying characteristics during startup stage are crucial for powder engine ignitions. A modified two-fluid model was presented for dense powder conveying in startup stage in this paper, in which the μ(I) rheology theory was implanted to replace kinetic theory of granular flow. New constructed model was employed to investigate the unsteady conveying characteristics, and three distinct sub-stages of dense powder conveying at startup stage and its competitive mechanisms were confirmed. In addition, the relative volatility was introduced to assess the effect of peak rate, and it was found that increases in the fluidizing gas pressure or the throat diameter were beneficial to the stability of conveying. This paper provides a new numerical approach for predicting the startup behaviors of dense powder conveying, and offers new insights into the dynamics of dense powder conveying and references for the development of reliable ignition technology in powder fueled ramjets.