Niebuhr, Chantel MonicaSchmidt, S.Van Dijk, MarcoSmith, LelanieNeary, Vincent S.2022-07-152022-04Niebuhr, C.M., Schmidt, S., Van Dijk, M. et al. 2022, 'A review of commercial numerical modelling approaches for axial hydrokinetic turbine wake analysis in channel flow', Renewable and Sustainable Energy Reviews, vol. 158, art. 112151, pp. 1-18, doi : 10.1016/j.rser.2022.112151.1364-0321 (print)1879-0690 (online)10.1016/j.rser.2022.112151https://repository.up.ac.za/handle/2263/86218Computational fluid dynamics is employed for detailed prediction of the hydrokinetic turbine performance and wake modelling. Of these, Reynolds-averaged Navier-Stokes (RANS) models are most widely used due to their ability to resolve power performance and detailed flow features at relatively low computational costs and acceptable accuracy. The limitations of these models are often not well understood when applied to complex turbine and wake dynamics which could lead to potential inaccurate and inappropriate conclusions. This paper focuses on the prediction of the wake generation, dissipation and flow recovery using commercially available modelling software. The approach and findings of previous numerical investigations on this matter are reviewed and compared to experimental measurements reported for a dual-rotor reference turbine. The shortcomings of these models are discussed and appropriate modelling techniques for the preliminary design or analysis of hydrokinetic turbines and inland energy generation schemes are identified. Commercially available RANS models show a good correlation of turbine performance. However, prediction of the wake behaviour is improved by using a virtual disk model with the blade element momentum theory, employing Reynolds stress closure models. These models allow for modelling the anisotropic conditions in the wake unlike the more popular eddy viscosity models. In addition, simplified rotor geometry models using blade element momentum theory are found to adequately model wake development and dissipation at a modest computational expense. The shortcomings of other approaches in terms of wake dissipation prediction and the effect of boundary and inflow conditions are analysed, emphasizing the importance of correct prescriptions of model parameters.en© 2022 Elsevier Ltd. All rights reserved. Notice : this is the author’s version of a work that was accepted for publication in Renewable and Sustainable Energy Reviews . Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. A definitive version was subsequently published in Renewable and Sustainable Energy Reviews, vol. 158, art. 112151, pp. 1-18, 2022. doi : 10.1016/j.rser.2022.112151.Reynolds-averaged Navier-Stokes (RANS)HydrokineticComputational fluid dynamics (CFD)Wake-dissipationIn-land hydrokineticAxial flow turbinesWake-modellingEngineering, built environment and information technology articles SDG-04SDG-04: Quality educationEngineering, built environment and information technology articles SDG-06SDG-06: Clean water and sanitationEngineering, built environment and information technology articles SDG-07SDG-07: Affordable and clean energyEngineering, built environment and information technology articles SDG-09SDG-09: Industry, innovation and infrastructureEngineering, built environment and information technology articles SDG-13SDG-13: Climate actionPostprint Article