Flow field simulation and protective effectiveness research on sand barriers by computational fluid dynamics (CFD)- a review

Sand barriers are indispensable protective measures in the early stage of sand control, which could effectively increase subsurface roughness and reduce wind erosion. Advances in CFD techniques render simulation of airflow around sand barriers more efficient and intuitive, to accurately analyze airflow mechanisms and comprehensively optimize barrier design. Abundant CFD studies on sand barriers have been conducted, but a systematic review is still lacking. Based on four sets of keywords including barrier, CFD simulation, incoming flow conditions and shelter effect evaluation, we conducted a literature search on numerical simulation studies of sand barriers primarily in Web of Science core database by now, and 152 research papers were finally included. This paper presents the airflow and wind-blown sand flow structures around various types of sand barriers, systematically summarizes the impact of barrier geometrical parameters (porosity, height, shape, and arrangement) and incoming flow conditions (incoming wind speed and wind direction) on the protective effect of sand barriers, and provides a comprehensive summary of evaluation indexes on the shelter effect of sand barriers. On this basis, we discuss the irreplaceable advantage of CFD technology and the limitations of current research. Accordingly, we propose four aspects for future CFD research, including sand barrier optimization under real underlying surface conditions, simulations using realistic sand barrier models, research on flexible sand barriers, and investigations into comprehensive protective measures that integrate sand barriers. This study hopes to provide insight into CFD research and engineering application of sand barriers.