Anti-Erosion Characteristics of Novel Biomimetic Structures for High-Pressure Manifold Elbows

Literature Overview

This paper published in Chemical Engineering Equipment and Piping (2026, Vol. 63, No. 2, pp. 122–130) by Zhou Sizhu, Shen Wanhu, Wang Lingxiang, and Zeng Yun from Yangtze University and National Petroleum and Natural Gas Network Group Co., Ltd. Central China Branch investigates the anti-erosion performance of biomimetic surface structures applied to high-pressure manifold elbows. The research is supported by CNPC Science and Technology Innovation Fund (2024DQ02-0307) and National Natural Science Foundation of China (52174018, 51674040).

Core Technical Content

Biomimetic Design Concept

The research draws inspiration from the microstructure of shark skin, which is known for its exceptional hydrodynamic and erosion-resistant properties. Four biomimetic surface structures were designed and applied to thickened-wall elbows, and their anti-erosion performance was systematically evaluated through numerical simulation and orthogonal experimental design.

Performance Results

The biomimetic structures demonstrated significant improvements in anti-erosion performance compared to the conventional thickened-wall elbow:

Orthogonal Experimental Analysis

The study conducted an orthogonal experimental design to determine the relative importance of five structural parameters on erosion rate. The range analysis revealed the following parameter influence ranking:

1. Bottom peak incremental spacing (底峰递增间距) — highest influence
2. Bottom peak height (底峰高) — second highest influence
3. Top peak height (顶峰高) — third influence
4. Inter-peak spacing (两峰间距) — fourth influence
5. Top peak incremental spacing (顶峰递增间距) — lowest influence

Optimal Design Parameters

The optimal combination of design parameters was determined as follows:

Engineering Analysis

Mechanism of Biomimetic Anti-Erosion Effect

The biomimetic surface structures likely reduce erosion through several mechanisms:

• Flow disruption: The surface microstructure disrupts the boundary layer flow, reducing the effective particle impact velocity.
• Energy dissipation: The peaks and valleys provide additional surface area for energy absorption during particle impact.
• Particle deflection: The angled surfaces redirect particles away from direct normal impact, reducing damage per collision.
• Boundary layer modification: The surface roughness pattern may promote a more protective boundary layer that reduces particle-wall contact frequency.

Practical Implementation Considerations

While the simulation results are promising, several practical considerations must be addressed for field deployment:

Comparative Analysis with Conventional Approaches

Traditional approaches to elbow erosion mitigation include:

• Increasing wall thickness (addressed in this study as the baseline)
• Using erosion-resistant materials (hardened steel, ceramic composites)
• Applying protective coatings (thermal spray, electroplating)
• Installing erosion shields or diverter plates

The biomimetic approach offers a geometric solution that can be combined with material and coating strategies for synergistic protection. The 67.3% improvement achieved by the best variant represents a substantial advance that could significantly extend elbow service life in high-pressure fracturing applications.

Methodological Assessment

The use of orthogonal experimental design is appropriate for this study because it efficiently identifies the most influential parameters with a limited number of simulation runs. The range analysis provides clear guidance for design optimization. However, the following points warrant attention:

• The numerical simulation results require experimental validation through erosion testing.
• The orthogonal design explores a limited parameter space; multi-objective optimization may yield further improvements.
• The study does not address the long-term durability of the biomimetic structures under sustained erosion conditions.
• The interaction between biomimetic surface geometry and fluid flow characteristics (velocity, particle size distribution, flow regime) should be further investigated.

Key Insights

The parameter influence ranking is particularly valuable for engineering practice. The finding that bottom peak incremental spacing is the most influential parameter suggests that the overall pattern periodicity is more critical than individual peak geometry. This insight can guide rapid design iteration and optimization. Additionally, the optimal design achieving 20.2% improvement with relatively simple parameters (0.5 mm bottom peak, 2.0 mm top peak, 5 mm inter-peak spacing) represents a practical and potentially manufacturable solution.

Summary

This research demonstrates that biomimetic surface structures can significantly enhance the erosion resistance of high-pressure manifold elbows, with improvements ranging from 9.8% to 67.3% depending on the design variant. The orthogonal experimental analysis provides clear guidance on the most influential design parameters, with bottom peak incremental spacing identified as the primary optimization target. The optimal design parameters offer a practical starting point for engineering implementation. For the oil and gas industry, where high-pressure manifold elbows are critical components subject to severe erosion in fracturing operations, this biomimetic approach represents a promising avenue for extending component life and reducing operational costs. Future work should focus on experimental validation, manufacturing process development, and integration with existing coating and material strategies for comprehensive erosion protection.