Optimization-based method for conjugate heat transfer problems
Liang Fang, Xiandong Liu, Lei Zhang
TL;DR
This paper addresses efficient partitioned solution of conjugate heat transfer problems by pairing a semi-implicit finite-volume Navier–Stokes solver with an optimization-based coupling across the fluid–solid interface. The Navier–Stokes equations are advanced with an explicit treatment of convection and implicit pressure/diffusion, ensuring stability under a CFL-like condition $0\le C_m\le 1$, while the interface heat transfer is enforced by solving a constrained optimization problem for the interface flux $\mathbf{g}$ via sequential quadratic programming. A reduced representation $\mathbf{g}=\boldsymbol{\Phi}\boldsymbol{\beta}$ using Laplace–Beltrami eigenfunctions accelerates the optimization, yielding a fast, parallelizable coupling. Numerical experiments across lid-driven cavity, diffusion, flow over a heated plate, and natural convection demonstrate improved efficiency and robustness over traditional Dirichlet-to-Neumann or SIMPLE-based approaches, with accurate temperature continuity at the interface and stable, time-dependent flow fields. The work offers a flexible framework applicable with various fluid solvers and points to future enhancements such as factorization strategies, nearly implicit schemes, and Robin-type interface conditions to further boost performance.
Abstract
We propose a numerical approach for solving conjugate heat transfer problems using the finite volume method. This approach combines a semi-implicit scheme for fluid flow, governed by the incompressible Navier-Stokes equations, with an optimization-based approach for heat transfer across the fluid-solid interface. In the semi-implicit method, the convective term in the momentum equation is treated explicitly, ensuring computational efficiency, while maintaining stability when a CFL condition involving fluid velocity is satisfied. Heat exchange between the fluid and solid domains is formulated as a constrained optimization problem, which is efficiently solved using a sequential quadratic programming method. Numerical results are presented to demonstrate the effectiveness and performance of the proposed approach.
