Research Paper Estimating the wind pressure coefficient for single- span greenhouses using an large eddy simulation turbulence model Rack-woo Kim, In-bok Lee * , Uk-hyeon Yeo, Sang-yeon Lee Department of Rural Systems Engineering, Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, 599, Gwanakno, Gwanakgu, Seoul, 08826, Republic of Korea article info Article history: Received 18 December 2018 Received in revised form 3 October 2019 Accepted 8 October 2019 Keywords: Greenhouse Computational fluid dynamics Mean wind pressure coefficient Peak wind pressure coefficient Wind tunnel test The wind pressure coefficient (C p ) can be divided into a mean wind pressure coefficient (C p, mean ) and peak wind pressure coefficient (C p, peak ). In this study, the C p, mean and C p, peak values of single-span greenhouses were estimated using time-dependently computed large eddy simulation (LES) of the computational fluid dynamics (CFD) model. First, the C p, mean and C p, peak values of single-span greenhouses were measured through a wind tunnel test considering various experimental conditions, such as the roof slope and roof curvature radius. The CFD-computed C p, mean and C p, peak values were compared with those measured in the wind tunnel for the validation of the CFD model. Especially, the computed C p, mean values using the LES model were compared with the computed C p, mean values using the RANS model performed by Kim, Lee, and Kwon (2017). Consequently, the LES model predicted the C p, mean values more accurately than those predicted by the RANS. In addition, the C p, peak values computed using the LES model showed only fine differences with those measured in some other regions; however, the overall tendency was similar between the measured and computed C p, peak values. From these results, it was determined that the LES model can properly predict the C p, peak values as well as the C p, mean values. © 2019 IAgrE. Published by Elsevier Ltd. All rights reserved. 1. Introduction A greenhouse should be precisely designed based on the greenhouse standard because the greenhouse frames and cover materials could be easily destroyed by strong winds. However, the Korean greenhouse standards are not well- defined for wind loads, and they were made more than 20 years ago. Therefore, the effects of wind load on a greenhouse should be carefully evaluated to secure its structural safety. The wind pressure coefficient (C p ), which is a dimension- less coefficient according to the shape of greenhouses, is basically used to evaluate the wind load of a greenhouse. The C p value, which is defined as the ratio of static pressure dif- ference to the design velocity pressure, represents the wind pressure distribution on the surface of the greenhouse. The C p values have been mostly evaluated by field experiment, wind tunnel test, and computational fluid dynamics (CFD). Various field experiments have been conducted to investigate the characteristics of the wind pressure acting on a low-rise * Corresponding author. Fax: þ82 2 873 2087. E-mail address: iblee@snu.ac.kr (I.-b. Lee). Available online at www.sciencedirect.com ScienceDirect journal homepage: www.elsevier.com/locate/issn/15375110 biosystems engineering 188 (2019) 114 e135 https://doi.org/10.1016/j.biosystemseng.2019.10.009 1537-5110/© 2019 IAgrE. Published by Elsevier Ltd. All rights reserved.