基于相似原理的粗糙表面接触密封泄漏预测方法OA

To address the challenge of predicting leakage between grid plates of ceramic grid seal structures for hypersonic aircraft,a numerical analysis method integrating similarity principle and flow factor was proposed.A 3D rough surface model was constructed using Abaqus/RufGen and scaled up proportionally.Subsequently,smooth and rough leakage region models at the same scale were established.The flow factor was obtained through simulation calculations.Finally,by combining the leakage rate of a smooth channel at the actual size,the leakage of the rough surface contact seal was predicted.The results indicate that the similarity principle effectively correlates the leakage characteristics of models at different scales.The leakage rate is synergistically regulated by temperature,pressure ratio,and gap height.Under the extreme condition of a pressure ratio of 7 and an operating temperature of 1 200 K,the leakage rate between grid plates with a roughness of 1.2 μm is approximately 1.3 mm3/s.The flow factor decreases with increasing roughness and decreases with increasing temperature.The"gap narrowing+resistance enhancement"dual effect between grid plates with small roughness significantly reduces the leakage rate.This study provides a reference for the design of contact seals under extreme environments.