Integrated Experimental-Numerical Analysis of HTPB Propellant Casting Optimization and Droplet Dynamics

Area of Science:

• Materials Science
• Chemical Engineering
• Fluid Dynamics

Background:

• Propellant slurry rheology and droplet dynamics are crucial for manufacturing.
• Hydroxyl-terminated polybutadiene (HTPB)-based composite solid propellants require precise casting.

Purpose of the Study:

• To investigate the rheological properties of HTPB-based propellant slurry.
• To optimize the vacuum casting process using experimental and numerical methods.
• To understand the impact of vacuum pressure on casting efficiency and droplet dynamics.

Main Methods:

• Rheological tests were conducted to determine slurry behavior.
• Herschel-Bulkley model was used to characterize non-Newtonian fluid properties.
• A real-time monitoring system with machine vision and Kalman filtering was employed.
• Numerical simulations were performed to validate experimental findings.

Main Results:

• The propellant slurry exhibited shear-thinning behavior.
• Slurry viscosity peaked at 41 Pa·s with coarse ammonium perchlorate (AP) particles, stabilizing at 17 Pa·s.
• Increased vacuum pressure (10-14 psi) improved casting efficiency but decreased droplet impact forces.
• Numerical simulations showed good agreement with experimental casting times (6.16%-11.07% deviation).

Conclusions:

• Vacuum pressure regulation is key to optimizing propellant casting parameters.
• Balancing casting efficiency and impact forces enhances propellant defect control.
• This research provides theoretical support for advanced propellant manufacturing processes.