Analysis on hydrodynamic characteristics and hydraulic transient method of hydraulic recoil brake for artillery

To address the issues of insufficient accuracy in traditional analytical method and low computational efficiency in Computational Fluid Dynamics (CFD) method for analyzing artillery hydraulic recoil mechanisms, an in-depth investigation of hydrodynamic characteristics is conducted. The operational states are categorized into transient and steady state. For the throttling effect in steady state, dimensional analysis is employed, and the relationship between throttling pressure difference and other physical quantities is established by CFD simulations, resulting in the formulation of the Throttling Equation (TE). Regarding transient effects, hydrodynamic transient equations are constructed and solved using the MUSCL-Hancock scheme. A three-chamber computational domain for the recoil brake is defined and updated via a moving boundary approach. Boundary conditions are implemented through the ghost cell, while a solution strategy for complex throttling orifice boundaries is developed utilizing TE. The Brake Hydraulic Transients Method (BHTM) is constructed eventually which reveals the pressure fluctuations in hydraulic recoil brake. Comparative analysis against firing experiment data is performed, testing BHTM against classical Bernoulli and CFD method. BHTM is demonstrated to capture transient effects and accuracy in predicting transient state pressure has improved by 15.84% compared to Bernoulli. BHTM achieves a 32-fold improvement in computational efficiency over CFD simulations, reducing processing time from 4 hours to 439 s with an acceptable accuracy trade-off of 13.6% decrease in transient pressure predictions. BHTM balances the accuracy and efficiency in recoil brake analysis.