Discrete Adjoint Approaches for CHT Applications in OpenFOAM

Conjugate Heat Transfer (CHT) simulations allow the prediction of complex interactions between fluid and solid mediums. Our application is the optimization of heat transfer between heat sinks and a cooling fluid, used to extract the heat from server infrastructure. Adjoint methods allow the optimization of high dimensional parameter settings, using sensitivity information. Compared to classical approaches to sensitivity generation, e.g. finite differences, a significant improvement in run time can be achieved, as the complexity of deriving the sensitivity scales with the output dimension, instead of the input (parameter) dimension. As an initial prove of concept, our discrete adjoint OpenFOAM framework has been extended to facilitate the differentiation of the chtMultiRegionSimpleFoam solver. To combat prohibitive memory loads a traditional and a novel checkpointing approach are used. We will present results of the heat transfer of a copper heat sink immersed in water.