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Three-Dimensional Digital Model Reconstruction and Seepage Characteristic Analysis of Porous Polyimide
Zhaoliang Dou1, Shuang Li1, Wenbin Chen1
1School of Mechanical and Materials Engineering, North China University of Technology, Beijing 100144, China.
Polymers
|March 14, 2026
Summary
This study reveals how lubricant oil flows through porous polyimide (PPI) materials for aerospace bearings. It found that oil preferentially flows through larger pore structures, demonstrating that material structure dictates flow behavior.
Area of Science:
- Materials Science
- Tribology
- Computational Fluid Dynamics
Background:
- High-speed aerospace bearings require advanced lubricating materials.
- Porous polyimide (PPI) is a promising material, but its lubrication mechanisms are not fully understood.
- Understanding lubricant transport in PPI's complex microstructure is crucial for performance optimization.
Purpose of the Study:
- To investigate the mesoscale seepage characteristics of lubricating oil in porous polyimide.
- To establish a link between the pore structure of PPI and lubricant flow behavior.
- To provide a reliable numerical tool for analyzing lubricant transport in PPI.
Main Methods:
- Reconstruction of a three-dimensional digital model of PPI microstructure using micro-focus X-ray computed tomography (CT).
- Development and validation of a multiple-relaxation-time lattice Boltzmann model (D3Q27) for seepage simulation.
- Simulation of single-phase lubricant oil seepage within the reconstructed PPI pore structure.
Main Results:
- Identified a strong 'preferential flow path' effect, where most lubricant flows through a few large pore throats.
- Established a quantitative relationship between microscopic flow field characteristics (velocity, pressure) and pore-topology features (connectivity, tortuosity).
- Confirmed the mesoscale mechanism that material 'structure governs flow' in porous polyimide.
Conclusions:
- The study provides a comprehensive technical chain from real-structure reconstruction to seepage mechanism analysis.
- The findings offer a reliable theoretical and numerical basis for understanding lubricant transport in PPI.
- Results guide the microstructural design and optimization of porous polyimide for enhanced lubrication in aerospace applications.
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