流-热-力耦合的高性能结构拓扑优化设计方法

A Topology Optimized Design Method for High-performance Structures with Fluid-thermal-mechanics Coupling

拓扑优化和增材制造技术的快速发展为高性能复杂装备提供了高效的产品设计和制造方法。目前高性能结构拓扑优化只考虑热-力耦合或者流-热耦合的设计,且大多局限于简单结构,未考虑流-热-力三场共同作用下的设计,限制了结构性能的提升。针对流-热-力多物理场工况下的高性能复杂结构设计这一挑战,提出了一种流-热-力耦合拓扑优化方法,以提高复杂结构的承温能力。首先引入流场、温度场和结构位移场的控制方程,对计算域的流固材料进行统一表征;然后以最小化平均温度为目标,以流动能量耗散和结构柔度为约束,建立了流-热-力耦合的拓扑优化模型,并结合变分法和拉格朗日函数开展了设计变量的灵敏度分析;最后将所建立的拓扑优化模型应用于涡轮的结构设计,得到了散热性能良好、流道分布合理的可增材制造结构。

The rapid advancement of topology optimization and additive manufacturing technology provided efficient methods for designing and manufacturing high-performance complex equipment.However,current topology optimization techniques for high-performance structures only considered the design of thermal-mechanics coupling or fluid-thermal coupling,and were mostly limited to simple structures.The design under the combined effects of fluid-thermal-mechanics fields was not considered,which restricted the enhancement of structural performance.This paper tackled the challenge of designing high-performance complex structures under multi-physics fields,encompassing fluid-thermal-mechanics interactions.A topology optimization method was proposed to enhance the ability to withstand temperature of intricate structures.Firstly,the governing equations of flow field,temperature field and structural displacement field were introduced to provide a unified description of the fluid-solid materials within the computational domain.Secondly,the topology optimization model was formulated with fluid-thermal-mechanics coupling.The objective function was set to minimize the average temperature,while flow energy dissipation and structural compliance served as constraint functions.Sensitivity analysis of design variables was carried out by using a combination of the variational method and Lagrangian function.Finally,the established topology optimization model was applied to the structural design of a turbine,resulting in a structure suitable for additive manufacturing with excellent heat dissipation performance and well-balanced flow channel distribution.