Principal CFD Scientist, Bioreactor Scale-Up Leader

Merck & Co.; Rahway (NJ); Hybrid; USD 173,000 - 273,000; Full time

Benefits offered by this job

Medical Insurance

Dental Insurance

Vision Insurance

401(k)

Paid Holidays

Flexible Work Arrangements

Job summary

Merck & Co., Inc. in Rahway, NJ seeks a Principal Scientist to lead CFD and engineering simulations for bioreactor scale-up.

You will own end-to-end modeling, validate against experiments, and collaborate with process development to define scale-up criteria across biologics and small-molecule operations. The role emphasizes leadership in transport phenomena, physics-based modeling, and engineering equivalence, with a hybrid work arrangement and a strong focus on enabling robust manufacturing

Qualifications

• Ph.D. in Chemical Engineering, Mechanical Engineering, Bioengineering, Physics, Biology, Chemistry, Data Science or closely-related field with 6+ years experience.
• MS in Chemical Engineering, Mechanical Engineering, Bioengineering, Physics, Biology, Chemistry, Data Science or closely-related field with 8+ years experience.
• BS in Chemical Engineering, Mechanical Engineering, Bioengineering, Physics, Biology, Chemistry, Data Science or closely-related field with 10+ years experience.

Responsibilities

• Lead CFD and engineering simulation of bioreactor mixing and gassing to characterize P/V, shear, mixing time, pH and component gradients, kLa, and gas gradients toward defining engineering equivalence between development and manufacturing scales.
• Design scale-down models that reproduce the critical hydrodynamic and mass-transfer environment of the manufacturing-scale bioreactor, in partnership with process development scientists.
• Extend physics-based modeling to other sensitive bioprocess unit operations, including harvest (centrifugation, depth filtration) and TFF (UF/DF, viral filtration), to quantify shear and hydrodynamic risk to product quality.
• Own end-to-end modeling project execution: problem framing, geometry and mesh strategy, solver setup, validation against experimental data, and clear communication of predictions and their limitations to cross-functional stakeholders.
• Support vessel and site characterization studies and standard workplans to support enterprise scale-up/scale-down strategy.
• Mentor junior scientists on the Process Modeling & Analytics team; grow their technical judgment in transport phenomena, CFD methodology, and simulation-based decision making.
• Shape the team's modeling roadmap and establish practical standards for simulation workflows (case setup, HPC/cloud use, validation, reuse) that scale across the portfolio.
• Support engineering simulations extending from biologics to small-molecule organic drug substance unit operations (e.g., crystallization, reactor mixing) as pipeline needs require.

Skills

CFD expertise

Transport phenomena

Python

MATLAB

Education

Ph.D. in Chemical Engineering or related field

M.S. in Chemical Engineering or related field

B.S. in Chemical Engineering or related field

Tools

M-Star CFD

ANSYS Fluent

STAR-CCM+

COMSOL

OpenFOAM

Job description

Merck & Co., Inc. in Rahway, NJ seeks a Principal Scientist to lead CFD and engineering simulations for bioreactor scale-up.

You will own end-to-end modeling, validate against experiments, and collaborate with process development to define scale-up criteria across biologics and small-molecule operations. The role emphasizes leadership in transport phenomena, physics-based modeling, and engineering equivalence, with a hybrid work arrangement and a strong focus on enabling robust manufacturing