Arpan Sircar

Bio

Dr. Arpan Sircar is a CFD Applications Engineer in the Multiphysics CFD Applications Group of the Nuclear Energy and Fuel Cycle Division at Oak Ridge National Laboratory (ORNL). Arpan received his Bachelors in Mechanical Engineering (2011) from Jadavpur University, M.Tech. (2013) in Mechanical Engineering with a specialization in Thermal-Fluids Engineering from the Indian Institute of Technology, Bombay and PhD (2019) in Mechanical Engineering from the Pennsylvania State University. In 2020, he did post-doctoral research in the Nuclear Engineering department of Texas A&M University. Following a two-year postdoc at ORNL from 2021-2022, he joined as a full-time Staff Researcher at ORNL. He has over 15 years of experience in computational fluid dynamics (CFD) modeling of turbulence and heat transfer for a variety of applications including fusion blankets, advanced fission reactors, supercritical flows through Nuclear reactors, Internal Combustion engine flows, and canonical flow configurations such as channel flows, pipe flows and flow past a cylinder. Other areas of expertise include radiation and combustion modeling for spray flames and in-cylinder fuel combustion, and biological flows such as blood flow through vasculature and air flow through modelled Human lungs. Arpan has worked extensively with the open-source CFD software, OpenFOAM, to develop and implement new models for simulations. At ORNL, he has been developing tools for exascale multi-physics simulations of fusion reactor blankets as a part of the Fusion Energy Reactor Models Integrator (FERMI) and Fusion REactor Design Assessment (FREDA) projects. He is working extensively on magnetohydrodynamics for fusion reactors and molten-salt reactors, and tritium transport modeling for fusion devices. He is leading an LDRD project to implement novel multiphase flow solvers for nuclear applications in the ORNL developed VertexCFD code. He is recipient of a DOE Infuse award to investigate neutronics-CFD coupling in inertial fusion devices in collaboration with Xcimer Energy Corporation. Arpan likes to explore other opportunities of CFD applications such as in the decarbonization space, fuel cells, internal combustion engines and biological systems.

Education

• PhD, Mechanical Engineering (Minor: Computational Science), Penn State University (2013-19)
• MTech, Mechanical Engineering (Specialization: Thermal-Fluids), Indian Institute of Technology, Bombay, India (2011-13)
• Bachelors in Mechanical Engineering, Jadavpur University, Kolkata, India (2007-11)

Technical Skills

• Experienced in Computational Fluid Dynamics simulations, modeling, development and multi-physics coupling using OpenFOAM
• Developing tools such as VertexCFD and integrating with codes like Festim for tritium transport, OpenMC for neutronics and IPS-Fastran for plasma physics.
• Experienced in large-scale, computationally-intensive simulations including parallel computations with MPI and GPU acceleration with Kokkos.
• Expert in turbulence modeling using Reynolds Averaged Navier Stokes (RANS) and Large Eddy Simulation (LES) techniques
• Skilled in heat transfer modeling including convective (buoyancy-driven and forced flows) and radiative (spectral models, RTE solvers and Marshak boundary conditions)
• Experienced in multi-phase, multi-scale and multi-physics simulations such as spray dynamics, soot and flame propagation in Internal Combustion engines and multi-code coupling using preCICE.
• Learning new tools such as Nek5000 and NekRS

Publications - Journals and Conferences

• "Impact of high-fidelity temperature feedback modeling on fusion blanket neutronics", Jin Whan Bae, Arpan Sircar, Katarzyna Borowiec, Vittorio Badalassi and Cami Collins, Nuclear Fusion, Volume 66, Number 3, DOI: 10.1088/1741-4326/ae3628
• "Progress in FREDA: A Multi-Fidelity Plasma-Engineering Integrated Modeling Platform for Fusion Reactor Design and Assessment.", Collins, C.S., Park, J.M., Badalassi, V., Archibald, R., Bae, J.W., Barnett, R.L., Bass, E.M., Borowiec, K., Sircar, A., et al., In DPP 2025.
• “MHD turbulence models for fusion reactor blankets”, A. Sircar, V. Badalassi, APS-DFD Conference, November 20 – 22, Indianapolis, 2022.
• “Multiphysics code coupling for fusion blankets”, A. Sircar, K. Borowiec, J. W. Bae, J. Solberg, V. Badalassi, ANS Winter Meeting, November 13 – 17, Phoenix, 2022.
• “FERMI: Fusion Energy Reactor Models Integrator”, V. Badalassi, A. Sircar, J. W. Bae, K. Borowiec, S. Smolentsev, J. M. Solberg, P. Huang, submitted to special issue of Fusion Science and Technology on large-scale fusion systems analysis after invitation.
• “Advanced finite-volume numerics and source term assumptions for G-Equation modelling of propane/air flames”, F. Perini, F. Chuahy, A. Sircar, D. Splitter, R. Reitz, SAE Technical Paper, 2022.
• “Multiphysics simulations for fusion reactor blankets”, A. Sircar, J. W. Bae, V. Badalassi, ANS Winter Meeting, November 30 – December 2, 2021.
• “Turbulent flow and heat flux analysis from validated large eddy simulations of flow past a heated cylinder in the near wake region”, A. Sircar, M. Kimber, S. Rokkam, G. Botha, Phys. Fluids 32 (2020, selected as Editor’s Pick)
• “Soot and spectral radiation modeling for high-pressure turbulent spray flames”, S. Fernandez, C. Paul, A. Sircar et al., Combustion and Flame Volume, 190, April 2018, Pages 402-415.
• “An assessment of CFD based wall heat transfer models in piston engines”, A. Sircar, C. Paul et al., 10^th US National Combustion Meeting, April 2017, College Park, MD.
•  “Turbulence Radiation coupling in boundary layers of heavy-duty diesel engines”, A. Sircar, C. Paul et al., SIAM International Conference on Numerical Combustion, April 2017, Orlando.
• “Coupling between Turbulent Boundary Layer and Radiative Heat Transfer under engine-relevant conditions”, A. Sircar, C. Paul et al., APS Division of Fluid Dynamics, November 2016, Portland.
• “Modeling Radiative Heat Transfer in Engines”, D. C. Haworth, S. P. Roy, J. Cai, A. Sircar, M. F. Modest, International Multidimensional Engine Modeling Meeting, SAE Congress 2015,  Detroit.
• “A Study of Air Flow and Particle Deposition in Modeled Airway of Human Lung”, Arpan Sircar, Mohan D Deshpande, Vinay Ballal. ANSYS India conference 2010, Bangalore.

Publications