Rarefied Flow Solver Developer

Flexcompute Inc.•Watertown, MA

About The Position

Flexcompute is seeking an experienced software developer to contribute to rarefied gas simulation software and an AI tool designed for GPUs. The role involves designing and implementing algorithms focused on speed, robustness, accuracy, and scalability. It offers the opportunity to work on rarefied gas prediction and artificial intelligence algorithms in a production environment and participate in product development, release, maintenance, and support. The role may also provide exposure to the company’s multiphysics simulation and design optimization technologies.

Requirements

Strong background in rarefied gas dynamics, fluid mechanics, structural mechanics, aeroacoustics, conjugate heat transfer, or an adjacent field.
Knowledge of numerical methods for solving rarefied flows, such as Direct Simulation Monte Carlo (DSMC), Particle-in-Cell (PIC), or lower-fidelity engineering methods; knowledge of solving discretized Navier–Stokes equations for compressible flows.
Basic knowledge of computational geometry and meshing requirements for CFD simulations.
Proven experience in and contributions to complex rarefied gas or CFD solvers.
Experience with C++ for scientific computing and Python or a similar language for scripting.
Master’s degree or PhD in an applicable technical field.
Familiarity with version control systems such as Git and the Linux command line.
0–3 years of industry experience.

Nice To Haves

Industry experience implementing and testing new features in commercial gas dynamics or CFD solvers.
Prior experience working collaboratively in a medium-sized distributed development team.
PhD in Computational Science and Engineering, Mechanical Engineering, or Aerospace Engineering.
Expertise in rarefied gas dynamics, including kinetic theory and molecular gas dynamics, plume impingement, plume-surface interactions, reacting plumes, lunar or Martian dust propagation, or Hall effect thrusters.
Expertise in DSMC or PIC techniques for modeling rarefied gases or plasmas.
Expertise in AI surrogate models of fluid dynamics.
Expertise in surface and volumetric meshing for CFD.
Experience developing scalable, parallel CFD solvers using CUDA, HIP, MPI, or OpenMP.

Responsibilities

Independently implement, test, and document new solver features.
Profile and optimize feature implementations to improve speed and scalability on CPUs and GPUs.
Contribute to a clean and maintainable API for various functionalities.
Contribute to source code maintenance, bug fixes, support, and other relevant software development activities.
Collaborate with teams developing agentic user interface and scientific visualization tools and technologies.
Collaborate with Product Management, QA, and Documentation teams to accomplish product milestones in a timely manner.
Follow sound software engineering practices to ensure code is maintainable, extensible, and robust.
Prioritize user experience by making fluid simulation complexity manageable through intuitive controls and straightforward workflows.
Deliver robust, high-performance simulations for industrial applications involving large amounts of data.