title: Experimental and numerical characterization of the water flow in spacer-filled channels of spiral-wound membranes.
abstract: Micro-scale flow distribution in spacer-filled flow channels of spiral-wound membrane modules was determined with a particle image velocimetry system (PIV), aiming to elucidate the flow behaviour in spacer-filled flow channels. Two-dimensional water velocity fields were measured in a flow cell (representing the feed spacer-filled flow channel of a spiral wound reverse osmosis membrane module without permeate production) at several planes throughout the channel height. At linear flow velocities (volumetric flow rate per cross-section of the flow channel considering the channel porosity, also described as crossflow velocities) used in practice (0.074 and 0.163 m·s(-1)) the recorded flow was laminar with only slight unsteadiness in the upper velocity limit. At higher linear flow velocity (0.3 m·s(-1)) the flow was observed to be unsteady and with recirculation zones. Measurements made at different locations in the flow cell exhibited very similar flow patterns within all feed spacer mesh elements, thus revealing the same hydrodynamic conditions along the length of the flow channel. Three-dimensional (3-D) computational fluid dynamics simulations were performed using the same geometries and flow parameters as the experiments, based on steady laminar flow assumption. The numerical results were in good agreement (0.85-0.95 Bray-Curtis similarity) with the measured flow fields at linear velocities of 0.074 and 0.163 m·s(-1), thus supporting the use of model-based studies in the optimization of feed spacer geometries and operational conditions of spiral wound membrane systems.
authors.affiliation: Water Desalination and Reuse Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia. Electronic address: Szilard.Bucs@kaust.edu.sa.
authors.forename: Szilard S
authors.initials: SS
authors.lastname: Bucs
authors.affiliation: Water Desalination and Reuse Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia. Electronic address: Rodrigo.Valladares@kaust.edu.sa.
authors.forename: Rodrigo Valladares
authors.initials: RV
authors.lastname: Linares
authors.affiliation: Department of Chemical Engineering, Texas Tech University, Lubbock, TX, 79409, USA. Electronic address: Jeremy.Marston@ttu.edu.
authors.forename: Jeremy O
authors.initials: JO
authors.lastname: Marston
authors.affiliation: Department of Biotechnology, Faculty of Applied Sciences, Delft University of Technology, Julianalaan 67, 2628, BC Delft, The Netherlands; Chair of Building Physics, Swiss Federal Institute of Technology Zürich (ETHZ), Stefano-Franscini-Platz 5, 8093, Zürich, Switzerland. Electronic address: Radu@arch.ethz.ch.
authors.forename: Andrea I
authors.initials: AI
authors.lastname: Radu
authors.affiliation: Water Desalination and Reuse Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia; Department of Biotechnology, Faculty of Applied Sciences, Delft University of Technology, Julianalaan 67, 2628, BC Delft, The Netherlands; Wetsus, European Centre of Excellence of Sustainable Water Technology, Oostergoweg 9, 8911 MA, Leeuwarden, The Netherlands. Electronic address: J.S.Vrouwenvelder@tudelft.nl.
authors.forename: Johannes S
authors.initials: JS
authors.lastname: Vrouwenvelder
authors.affiliation: Department of Biotechnology, Faculty of Applied Sciences, Delft University of Technology, Julianalaan 67, 2628, BC Delft, The Netherlands. Electronic address: C.Picioreanu@tudelft.nl.
authors.forename: Cristian
authors.initials: C
authors.lastname: Picioreanu
mesh_terms: D005374:Filtration / Q000379:methods*; D057446:Hydrodynamics; D008962:Models, Theoretical; D016062:Porosity; D012212:Rheology; D014872:Water Movements; D018508:Water Purification / Q000379:methods*
keywords: Computational fluid dynamics (CFD); Membrane filtration; Particle image velocimetry (PIV); Spacer; Spiral-wound membrane module