An approach to verification and validation of MHD codes for fusion applications S. Smolentsev 1, ∗ , S. Badia 2,3 , R. Bhattacharyay 4 , L. Bühler 5 , L. Chen 10 , Q. Huang 6 , H.-G. Jin 7 , D. Krasnov 8 , D.-W. Lee 7 , E. Mas de les Valls 2,3 , C. Mistrangelo 5 , R. Munipalli 9 , M.-J. Ni 10 , D. Pashkevich 11 , A. Patel 3 , G. Pulugundla 1 , P. Satyamurthy 12 , A. Snegirev 11 , V. Sviridov 13 , P. Swain 12 , T. Zhou 6 , O. Zikanov 14 1 University of California, Los Angeles, USA 2 Centre Internacional de Mètodes Numèrics en Enginyeria, Barcelona, Spain 3 Universitat Politècnica de Catalunya – Barcelona Tech, Spain 4 Institute for Plasma Research, Gandhinagar, Gujarat, India 5 Karlsruhe Institute of Technology, Germany 6 Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui, China 7 Korea Atomic Energy Research Institute, Daejeon, South Korea 8 Technische Universität Ilmenau , Germany 9 HyPerComp, Westlake Village, USA 10 University of Chinese Academy of Sciences, Beijing, China 11 St.Petersburg State Polytechnical University, Russia 12 Bhabha Atomic Research Center, India 13 Moscow Power Engineering Institute, Russia 14 University of Michigan – Dearborn, USA _______________________________________________________________________ Abstract We propose a new activity on verification and validation (V&V) of MHD codes presently employed by the fusion community as a predictive capability tool for liquid metal cooling applications, such as liquid metal blankets. The important steps in the development of MHD codes starting from the 1970s are outlined first and then basic MHD codes, which are currently in use by designers of liquid breeder blankets, are reviewed. A benchmark database of five problems has been proposed to cover a wide range of MHD flows from laminar fully developed to turbulent flows, which are of interest for fusion applications: (A) 2D fully developed laminar steady MHD flow, (B) 3D laminar, steady developing MHD flow in a non-uniform magnetic field, (C) quasi- two-dimensional MHD turbulent flow, (D) 3D turbulent MHD flow, and (E) MHD flow with heat transfer (buoyant convection). Finally, we introduce important details of the proposed activities, such as basic V&V rules and schedule. The main goal of the present paper is to help in establishing an efficient V&V framework and to initiate benchmarking among interested parties. The comparison results computed by the codes against analytical solutions and trusted experimental and numerical data as well as code-to-code comparisons will be presented and analyzed in companion paper/papers. Keywords: Blanket; Liquid metal magnetohydrodynamics; Computer code _____________________________________________________________ ∗ Corresponding author. Tel.: +1 310 794 5354. E-mail address: sergey@fusion.ucla.edu (S. Smolentsev).