Senior Simulation Engineer

Mainspring Energy manufactures and delivers fuel-flexible, low-emissions local power solutions that rapidly add new capacity and deliver reliable, affordable, and sustainable electric power. The company began commercial shipments of its Mainspring Linear Generators in 2020 and today has hundreds of megawatts in advanced development and field operations for leading Fortune 500 companies, data centers, and utilities. Mainspring also partners with global energy leaders including AEP, NextEra Energy Resources, Schneider Electric, and more.

The core values that ground our work, guide our decisions, and connect us together:

• Pragmatic Optimism
• Excellence without Ego
• Proactive Collaboration

Mainspring is seeking a Senior Simulation Engineer to own the structural and thermal simulation work that drives design decisions on our Linear Generator platform. In this role, you will embed with Mechanical project teams, build and calibrate Ansys Workbench models, and run closed loop, simulation driven design iterations that make hardware more reliable and cost effective while meeting all requirements.

This role is intended for engineers who have spent most of their career doing hands on FEA in Ansys Workbench, want to keep deepening that expertise, and have repeatedly turned simulation results into design changes that held up in test. A strong candidate treats every model as unproven until it matches hand calculations and test data, states clearly how much confidence a result deserves, and works closely with design owners, test, and manufacturing to close the loop.

• Own the simulation workstream within significant mechanical projects, from defining theanalysis questions, load cases, and acceptance criteria through results, recommendations, anddesign sign-off

• Build, run, and maintain static structural, thermal, modal, and buckling models in Ansys Workbench, from single parts to large assemblies with bolted joints and contact interfaces, and assess fatigue, joint slip and separation, and bolt integrity

• Drive closed loop, simulation driven design iterations with design owners, using parametric studies, sensitivity analysis, and optimization to reach designs that are more reliable and cost effective while meeting all requirements

• Benchmark and calibrate models against analytical calculations and unit or component test data, sanity check results with deformed shapes and reaction load balance, and document assumptions, boundary conditions, mesh convergence, and the confidence limits of each result

• Partner with test engineers to define instrumentation and test plans that produce the data needed to validate models, and feed test, production, and field results back into model fidelity

• Communicate results, risks, and recommendations clearly in design reviews and risk reviews, including what drives each result (load case, mean vs. alternating stress, contact pressure vs. shear), so designers know what to change

• BS or MS in Mechanical Engineering or a similar engineering field, with most of your career spent doing hands on FEA in Ansys Workbench on real hardware programs, and a clear interest in continuing to grow as a simulation specialist

• Fluency in Ansys Mechanical or equivalent for static structural, steady state thermal, thermal structural, modal, and buckling analysis, including element selection (tet vs. hex, element order, hells, beams), bonded and frictional contact, remote points and MPC/RBE connections, bolt pretension, submodeling, and inertia relief. This includes large assembly models that take hours to solve and debugging solver errors and under constrained bodies; experience limited to CAD embedded simulation tools is not sufficient

• Strong fundamentals in solid mechanics, heat transfer, fatigue (including Goodman or Gerber mean-stress correction), and failure theory, with a habit of checking simulation results against hand calculations and first principles estimates

• Hands-on experience matching and calibrating models to unit or component test data, and quantifying how well a model predicts reality before using it to make design decisions

• Proven track record of simulation driven insights that made designs more reliable, cost effective, or both, with results confirmed in validation testing, production, or the field

• Strong collaboration and communication skills, including the ability to embed in a project team, challenge weak assumptions, and present results with clear recommendations to technical and non-technical stakeholders

• MS or PhD with a focus in computational mechanics, fatigue and fracture, or thermal-structural analysis