TY  - EJOU
AU  - Tian, Maopeng 
AU  - Cao, Fan 
AU  - He, Xinlei 
AU  - Zhu, Caicheng 

TI  - Adaptive Density Regularization for Pressure Stabilization in Weakly Compressible SPH Modeling of Free Surface Impact Flows
T2  - Computer Modeling in Engineering \& Sciences

PY  - 
VL  - 
IS  - 
SN  - 1526-1506

AB  - Weakly compressible smoothed particle hydrodynamics (WCSPH) is widely used for computational modeling of violent free surface flows, but the equation of state pressure is sensitive to density error, deficient wall support, and local particle disorder. We develop an adaptive density regularization method for pressure stabilization in WCSPH. The method computes the raw summation density, a local kernel averaged density, and a bounded blended density used only for pressure evaluation through the Tait equation of state. The transport density definition, particle mass, and diagnostic density are retained; particle motion is affected only through the pressure values supplied to the standard momentum discretization. The blending coefficient is activated by density fluctuation, support count deviation, and wall proximity information. A dam break calibration selects alpha max, eta0, and the wall proximity length, which are then fixed in sloshing, dam break, and compact impact tests. Relative to baseline WCSPH, uniform pressure density smoothing, and standard delta-SPH, the adaptive scheme reduces sloshing pressure RMSE from 6.32 to 5.43 kPa and high frequency pressure energy by 41.5% while keeping the refined reference impulse error at 0.0%. The tested delta-SPH configuration damps the sloshing signal more strongly, but changes the refined reference impulse by 105.6% and reduces the compact impact peak pressure by 56.5% relative to WCSPH. In the compact impact case, the adaptive scheme changes the WCSPH peak pressure only marginally while reducing pressure oscillations. The results show that the proposed regularization provides a local pressure stabilization module for WCSPH that reduces high frequency pressure content while retaining diagnostic density and key response measures.
KW  - Computational modeling; smoothed particle hydrodynamics; WCSPH; pressure stabilization; density regularization

DO  - 10.32604/cmes.2026.087682