Aquacultural Engineering 102 (2023) 102343 Available online 19 May 2023 0144-8609/© 2023 Elsevier B.V. All rights reserved. Sedimentation effciency evaluation of an aquaculture tank through experimental foc characterization and CFD simulation Boris Miguel L´ opez-Rebollar , Daury García-Pulido , Carlos Diaz-Delgado , Ivan Gallego-Alarc´ on , Juan Antonio García-Arag´ on , Humberto Salinas-Tapia * Instituto Interamericano de Tecnología y Ciencias del Agua, Universidad Aut´ onoma del Estado de M´ exico, Carretera Toluca-Atlacomulco km 14.5, Toluca, Estado de M´ exico 50200, Mexico A R T I C L E INFO Keywords: Sedimentation CFD Aquaculture Floc characterization PTV Discrete phase model ABSTRACT One of the most important parameters for the proper functioning of an aquaculture tank is water quality. The survival and healthy growth of fsh depends on it. The main factors affecting water quality are the remains of food and feces of fsh which form cohesive particles called focs that are kept within the tank or in the modules of the recirculating aquaculture system (RAS). Through the application of non-invasive optical techniques such as particle tracking velocimetry (PTV) it was possible to experimentally characterize the particles from aquaculture tanks obtaining diameters and settling velocity distribution, which allowed estimating the effective density of the focs. With these parameters, the discrete phase model (DPM) was applied using computational fuid dynamics (CFD) to estimate the position and velocity of the particles within a prototype tank with geometry that promotes hydrodynamics suitable for particles sedimentation while maintaining the conditions for fsh growth. Through an experimental validation it was verifed that by having a tank with circular geometry, central settler made of concentric cylinders, perimeter gratings and outlet spillway cone, it is possible to achieve an effciency of 77.91–90% of particles sedimentation not exceeding 1 h in the process. Thus, through computer simulation coupled with experimental validation, it was possible to establish geometric parameters for the design of aquaculture tanks with self-cleaning characteristics under the sustainable scheme of water recirculation and reuse. 1. Introduction The use of Recirculating Aquaculture Systems (RASs) has become an alternative to traditional methods of intensive production of various fsh species. RASs are environmentally friendly because there is no discharge of water from the system in any regular form and they can even utilise harvested rainwater (Gallego-Alarc´ on et al., 2019), eliminating the need to be near a river, spring, or other body of water. Oca and Masal´ o (2012) wrote that optimal hydrodynamic conditions in aquaculture tanks are determined by the requirements of the species and disposal of waste. However, Davidson and Summerfelt (2004) described the effciency of utilising circular tanks for fsh culture. With this geometry, ponds exhibit self-cleaning characteristics when the primary rotational fow rate creates a radial secondary fow from the walls to the centre of the tank. This has a positive effect on the channelling of solids towards the centre of the tank for further extraction. Recent research has established that internal confgurations in aquaculture tanks can control hydrody- namics, directly infuencing the morphology of solid particles within the tank. That is why the design and optimization of the geometric com- ponents of a RAS continues to be a priority to guarantee self-cleaning and high effciency in the solids removal to achieve the objectives of sustainable development in aquaculture (Zhao et al., 2022). An alternative to optimising the experimental processes of aquacul- ture tank analysis and design is to use numerical modelling, such as computational fuid dynamics (CFD). CFD provide a numerical and approximate solution to the governing equations of fuid dynamics, namely continuity, momentum, and energy (Chung, 2014). With CFD, it is possible to perform simulations of processes or units at both the lab- oratory and real or commercial scales. This leads to better design and effciency improvements with respect to hydrodynamics and solid removal while avoiding discrepancies in the application of similarity analysis (Labatut et al., 2015a; 2015b). * Corresponding author. E-mail addresses: bmlopezr@uaemex.mx (B.M. L´ opez-Rebollar), dgarciap@uaemex.mx (D. García-Pulido), cdiazd@uaemex.mx (C. Diaz-Delgado), iga@uaemex. mx (I. Gallego-Alarc´ on), jagarciaa@uaemex.mx (J.A. García-Arag´ on), hsalinast@uaemex.mx (H. Salinas-Tapia). Contents lists available at ScienceDirect Aquacultural Engineering journal homepage: www.elsevier.com/locate/aque https://doi.org/10.1016/j.aquaeng.2023.102343 Received 6 December 2022; Received in revised form 13 April 2023; Accepted 17 May 2023