Stagiaire en performance des procédés et thermique (H/F)

This is an opportunity to work alongside an outstanding, multidisciplinary engineering team in a fast-paced startup environment. You will be part of Rondo's Core Technology team and contribute directly to the analysis and development of thermal and fluid systems at the heart of our high-temperature heat battery platform - performing real engineering calculations that shape how our systems are designed, optimized, and deployed.

What You Will Do

• Support thermal and fluid performance analyses using 1D simulation tools (e.g., AFT, Ebsilon, Aspen, or equivalent) and first-principles hand calculations to characterize system behavior across operating conditions.
• Assist in sizing and performance evaluation of fluid system components including pumps, blowers, fans, heat exchangers, valves, dampers, and air-flow equipment.
• Develop and validate steady-state and transient thermal models for energy storage and heat transfer systems, comparing simulation outputs against test data and analytical predictions.
• Perform pressure drop, flow distribution, and energy balance calculations for ducting networks, piping systems, and process loops.
• Apply fundamental thermodynamic and fluid mechanics principles to evaluate system efficiency, identify performance bottlenecks, and support design improvements.
• Assist in developing and maintaining engineering calculation packages, spreadsheets, and simulation scripts used for design verification and performance tracking.
• Support test planning and data reduction: process raw test data, produce performance plots, and compare results against model predictions.
• Contribute to equipment specification and vendor data review for pumps, blowers, heat exchangers, and related process equipment.
• Participate in design reviews and technical discussions; prepare concise technical memos and summaries as needed.

What You Will Bring

• Currently pursuing a Bachelor's or Master's degree in Mechanical Engineering, Chemical Engineering, or a related discipline; completion of core coursework in thermodynamics, fluid mechanics, and heat transfer required. Master's degree is preferred.
• Foundational understanding of energy systems, including thermal cycles, heat exchangers, pumps, blowers, fans, and air-handling equipment.
• Familiarity with 1D thermal-fluid analysis: ability to set up energy and mass balances, apply Bernoulli and Darcy-Weisbach principles, and interpret pump and fan curves.
• Exposure to at least one simulation or calculation tool such as AFT, Ebsilon, MATLAB, Aspen Plus/HYSYS, or equivalent; willingness to learn new tools quickly.
• Comfort working with engineering equations and unit conversions across SI and imperial systems.
• Strong academic record with a genuine interest in clean energy, climate technology, and sustainability.
• Attention to detail and commitment to producing accurate, well-documented engineering calculations.
• Organized self-starter with excellent time management skills and the ability to take ownership of assigned work.
• Effective communicator with strong writing skills and the ability to present technical results clearly to peers and senior engineers.

Bonus Points!

• Hands-on coursework or project experience with heat exchanger design, pump/fan system analysis, or duct/air system sizing.
• Familiarity with CFD/FEA tools for flow visualization or validation.
• Exposure to energy storage, renewable energy, industrial thermal systems, or power plant operations.
• Prior internship or co-op experience in a mechanical, process, or energy engineering environment.

What We Offer

• Catered lunches on-site
• Rondo HQ is close to Oakland airport - one block from the Bay - and has stunning Bay views!

This role necessitates either being on-site at our Alameda HQ 2-3x per week OR remote in Central Florida. The estimated annual hourly range for this role is $35 to $45. Please note that some pay bands may have wide ranges of compensation to accommodate candidates' diverse sets of skill levels and experience.