AMORE: Adaptive Multi-Output Operator Network for Stiff Chemical Kinetics
To address the computational efficiency bottleneck in CFD simulations of reactive systems—such as combustion and hypersonic flows—caused by stiff chemical kinetics, this work proposes a multi-output adaptive neural operator framework. Methodologically, it integrates DeepONet and Fourier Neural Operator (FNO) architectures, employs an adaptive weighted loss function to differentially penalize variable- and sample-wise errors, enforces physical consistency via an invertible analytical mapping that rigorously satisfies mass-fraction conservation and unity-sum constraints, and adopts a two-stage training strategy with dimensionality-reduction transformations to enhance generalizability. Experiments on syngas (12-species) and GRI-Mech 3.0 (24-species) mechanisms demonstrate that the model accelerates thermochemical state evolution prediction by one to two orders of magnitude over conventional implicit ODE solvers, while maintaining high fidelity. The framework serves as a robust, physics-informed acceleration module for turbulent combustion CFD simulations.