Hello, A yearly allocation for the LCRC cluster has been requested with the following updated information: Submitter/PI: Dillon Shaver Project Name: CMFD-RANS Division: NE Project title: Development of Multiphase RANS turbulence models Associated funding: NEAMS LDRD Other Systems: Mira - shared project has ~25M CPU hours Science: The objective of this project is to develop and implement Unsteady Reynolds Averaged Navier-Stokes (uRANS) turbulence models in the Nek5000/Nek2P CFD code for use in multi-phase flow simulations. Project description: RANS and uRANS turbulence models are necessary for the accurate CFD simulation of flows on large scales, such as nuclear reactor fuel rod bundles and full cores. The current state-of-the art for simulation of boiling flows utilizes the RANS framework. Recently, developments and improvement to the Nek-2P CFD code have allowed for the successful implementation of the algebraic mixing length turbulence model. This demonstrates that Nek-2P is mature enough to successfully implement more sophisticated two-equation type RANS models. Specifically, changes to the splitting algorithm have allowed Nek-2P to reach much higher time step sizes, close to the CFL limit. Additionally, with recent advances in RANS model implementation in Nek5000, the available RANS models are no longer limited to the k-omega family. The main goal of this project will be to extend the available turbulence models in Nek-2P to include at least one two-equation model (e.g. k-omega, k-epsilon). This will enable the further development and validation of multi-phase models with Nek and the subsequent simulation of large, complex problems of interest in both science and industry. Additionally support for the development of the turbulence models will include fundamental simulations such as flow over a cylinder. This project will use the CFD code Nek5000 and its multiphase branch, Nek-2P. Written in a combination of Fortran and C, Nek has been demonstrated to be a highly scalable code using the MPI library. Nek5000 has a long history of use and development on the LCRC systems. Proposed simulations will include helical pipe heat exchangers, nuclear reactor subchannels, as well as more fundamental problems such as flow around cylinders. Meshes for these problems range in size from <100K elements to >1M elements. The project is expected to have between 2-4 members. Industry partnership: Project URL: Current FY Hours Used: undetermined amount New FY Requested allocation: 200000 Q1: 50000 Q2: 50000 Q3: 50000 Q4: 50000 Justification: Storage requirements: 1TB Thank You, The LCRC Accounts System