Preprint
Large Language Models

LLM for Engineering

Toby Simonds
April 27, 2025arXiv.org3 citations

3

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Influential Citations

arXiv.org

Venue

2025

Year

Abstract

Large Language Models (LLMs) have transformed software engineering, but their application to physical engineering domains remains underexplored. This paper evaluates LLMs' capabilities in high-powered rocketry design through RocketBench, a benchmark connecting LLMs to high-fidelity rocket simulations. We test models on two increasingly complex design tasks: target altitude optimization and precision landing challenges. Our findings reveal that while state-of-the-art LLMs demonstrate strong baseline engineering knowledge, they struggle to iterate on their designs when given simulation results and ultimately plateau below human performance levels. However, when enhanced with reinforcement learning (RL), we show that a 7B parameter model outperforms both SoTA foundation models and human experts. This research demonstrates that RL-trained LLMs can serve as effective tools for complex engineering optimization, potentially transforming engineering domains beyond software development.

Analysis

Why This Paper Matters

This paper addresses a critical gap in the application of Large Language Models (LLMs) to physical engineering domains. While LLMs have revolutionized software engineering, their potential in fields like mechanical, aerospace, or civil engineering remains largely untapped. By introducing RocketBench, the authors provide a concrete, reproducible benchmark that connects LLMs to high-fidelity simulations, enabling systematic evaluation of LLM capabilities in engineering design tasks. This is a significant step toward understanding how LLMs can be leveraged beyond code generation and into complex, iterative design processes.

The paper's findings are particularly important because they highlight a key limitation of current LLMs: while they possess strong baseline knowledge, they struggle to effectively use simulation feedback to improve their designs. This is a common challenge in real-world engineering, where design is an iterative process of simulation, analysis, and refinement. The fact that RL-enhanced LLMs can overcome this limitation and even surpass human experts suggests a promising path forward for AI-assisted engineering, potentially accelerating innovation in fields that rely heavily on physical simulations.

Technical Contributions

  • RocketBench Benchmark: A novel benchmark that integrates LLMs with high-fidelity rocket simulations, providing a testbed for evaluating LLM-driven engineering design. The benchmark includes two tasks of increasing complexity: target altitude optimization and precision landing.
  • Evaluation of Base LLMs: The paper systematically evaluates state-of-the-art LLMs on these tasks, revealing their strengths in baseline knowledge and their weaknesses in iterative design refinement.
  • Reinforcement Learning Enhancement: The authors demonstrate that applying reinforcement learning to a 7B parameter LLM significantly improves its ability to iterate on designs, leading to performance that exceeds both SoTA foundation models and human experts.
  • Comparison with Human Performance: The benchmark includes human expert performance, providing a clear baseline for assessing the practical utility of LLMs in engineering optimization.

Results

The paper reports that while state-of-the-art LLMs demonstrate strong baseline engineering knowledge, they struggle to iterate on their designs when given simulation results, ultimately plateauing below human performance levels. This indicates a fundamental limitation in current LLMs' ability to close the loop between simulation and design modification. However, when enhanced with reinforcement learning, a 7B parameter model outperforms both SoTA foundation models and human experts. This is a striking result, as it suggests that a relatively small model, when trained with RL, can surpass much larger models and even human specialists in a complex engineering task. The specific metrics (e.g., altitude accuracy, landing precision) are not detailed in the abstract, but the qualitative comparison is clear.

Significance

The broader impact of this work is substantial. It demonstrates that RL-trained LLMs can serve as effective tools for complex engineering optimization, potentially transforming engineering domains beyond software development. This opens up new avenues for AI-assisted design in aerospace, automotive, and other physical engineering fields, where simulation-driven optimization is critical. The success of a 7B model also suggests that RL can unlock the potential of smaller, more efficient models, making advanced AI engineering tools more accessible. Furthermore, the RocketBench benchmark provides a foundation for future research, enabling the community to track progress in LLM-based engineering design. This paper is a significant step toward bridging the gap between LLMs and physical engineering, with implications for both AI research and industrial practice.