Distributed computing for physics-based data-driven reduced modeling at scale: Application to a rotating detonation rocket engine
Ionut-Gabriel Farcas, Rayomand P. Gundevia, Ramakanth Munipalli, Karen E. Willcox
TL;DR
The paper tackles the computational bottleneck of high-fidelity RDRE simulations by introducing a distributed memory data-driven ROM framework. It presents dOpInf, a distributed Operator Inference workflow that combines distributed data transformations, a POD-free dimensionality reduction, and parallel learning of reduced operators to produce physics-informed ROMs at scales unreachable by serial methods. On a real large-scale RDRE, the approach demonstrates strong and weak scaling up to 2{,}048 cores on Frontera, constructing a predictive ROM from $n_t=2{,}536$ snapshots of dimension $m=75{,}675{,}600$ in $13$ seconds and achieving a $9.0\times 10^4$ speedup over the full model, with ROM evaluations around $1.09$ seconds per core. The results show that the ROM captures large-scale RDRE features (e.g., three co-rotating waves) and enables efficient design exploration and uncertainty quantification, marking a practical step toward HPC-enabled data-driven propulsion design.
Abstract
High-performance computing (HPC) has revolutionized our ability to perform detailed simulations of complex real-world processes. A prominent contemporary example is from aerospace propulsion, where HPC is used for rotating detonation rocket engine (RDRE) simulations in support of the design of next-generation rocket engines; however, these simulations take millions of core hours even on powerful supercomputers, which makes them impractical for engineering tasks like design exploration and risk assessment. Data-driven reduced-order models (ROMs) aim to address this limitation by constructing computationally cheap yet sufficiently accurate approximations that serve as surrogates for the high-fidelity model. This paper contributes a distributed memory algorithm that achieves fast and scalable construction of predictive physics-based ROMs trained from sparse datasets of extremely large state dimension. The algorithm learns structured physics-based ROMs that approximate the dynamical systems underlying those datasets.This enables model reduction for problems at a scale and complexity that exceeds the capabilities of standard, serial approaches. We demonstrate our algorithm's scalability using up to $2,048$ cores on the Frontera supercomputer at the Texas Advanced Computing Center. We focus on a real-world three-dimensional RDRE for which one millisecond of simulated physical time requires one million core hours on a supercomputer. Using a training dataset of $2,536$ snapshots each of state dimension $76$ million, our distributed algorithm enables the construction of a predictive data-driven reduced model in just $13$ seconds on $2,048$ cores on Frontera.
