含硼凝胶燃料流变特性OA

Boron-loaded gel fuel is an ideal propellant for limited-volume propulsion devices such as ramjets.How-ever,its high viscosity and complex rheological properties pose significant challenges to its practical application.In this study,a novel gel fuel with 50wt%boron content was used as the research object.Based on the complex service en-vironments in engineering applications,a series of experiments were designed to investigate the effects of shear rate change rate,constant shear duration,pre-shearing,and temperature on the viscosity of boron-loaded gel fuel.The experimental phenomena were analyzed in depth based on shear stress.The results show that under constant shear rate,the time-dependent viscosity of boron-loaded gel fuel can be accurately described by a power function with a con-stant term.Pre-shearing can effectively destroy the structure of the boron-loaded gel system and make it difficult to re-cover within a finite time.High-low temperature cycling can hardly destroy the gel structure but can reduce its structural strength.At a constant shear rate,there exists a critical temperature:below this temperature,the viscosity of the gel fuel is negatively correlated with temperature;above this temperature,the viscosity does not change significantly.Based on shear stress analysis,it is inferred that the boron-loaded gel system has a multi-level structure.Under high-low temperature cycling,the recovery ability of the secondary structure is stronger than that of the main structure.