Calibration and comparison of different CFD approaches for airflow analysis in a glass greenhouse

Abstract

CFD has been increasingly applied to greenhouses to optimise indoor environmental conditions for cultivation and management. Numerical simulations have proved fundamental for the enhancement of energy-efficient design criteria and management procedures. The objective of the study is the comparison between different computational approaches for the study of airflow patterns in a representative study case of a glass greenhouse, also through the calibration of the models and the validation of simulation results against experimental data. A three-span greenhouse of about 300 m 2 located in Emilia-Romagna (Italy) has been considered as study case. Several analyses with the same boundary and initial conditions were performed using two codes, broadly used for research and design purposes. With both programs, 2D or 3D models have been used and, for every case, the grid convergence was verified by performing multiple steady state analyses with increasingly finer meshes. The results led to define the most suitable solutions to set up computational models for the simulation of airflow patterns inside a greenhouse. The study provided a preliminary outline of the differences due to the adoption of various computational approaches characterised by different levels of accuracy and complexity. The results indicate the advisability of further developing the research by carrying out deeper experimental insights necessary to quantify more in detail the validity and the reliability of the adopted analytical methodologies.

Research on the Microclimate of Protected Agriculture Structures Using Numerical Simulation Tools: A Technical and Bibliometric Analysis as a Contribution to the Sustainability of Under-Cover Cropping in Tropical and Subtropical Countries

“…Although, the accuracy achieved in the solution versus the computational cost and the memory available to store the data of the generated solution are quite debatable [91]. For more technical details, such as types of suitable numerical mesh, stability, and convergence time, the reader is referred to review the work of Molina-Aiz et al [91] and Benni et al [32]. Finally, another possibility is to use a combined method with FEM and FVM, such as the one running with the ANSYS CFX solver, which can often provide more accurate, stable, and faster solutions.…”

“…Simplified method 62 [19,32,[37][38][39]46,49,76,78,83,91,95,99,100,106,[108][109][110][111][113][114][115][116][120][121][122][123]126,129,131,133,136,[141][142][143][144][145][146][147][148][149]151,[153][154][155][156][159][160][161][163][164]…”

“…However, 55.1% of the collected works did not consider the crop within the simulations developed (Table 15). Many studies justified the non-presence of the crop in their research, mainly because they sought to characterize ventilation rates and temperature and relative humidity distribution patterns under the worst-case scenario of a greenhouse in an empty condition [15,32,76]. Under this condition, much of the energy captured by the structure is converted into heat since there are no crop plants to serve as sinks or provide water vapor to help regulate the temperature through water evaporation [2].…”

“…Additionally, they only allow users to obtain a numerical value of the ventilation rate, but do not allow visualization and understanding of the movements of the air flows [20,30]. For some of these reasons, and taking into account the progress of engineering tools, in recent years, the use of computational fluid dynamics (CFD) has been proposed as an agile and accurate alternative for the study of natural ventilation in protected agricultural structures [31,32].…”

Determining of Water Chiller Usage Time on Potato Crop Based on Distribution Temperature of Root Zone

“…Secara garis besar penggunaan CFD meliputi konsep dari desain baru, pengembangan produk secara detail, analisis kegagalan, dan desain ulang. Kompleksitas dan realisme pendekatan komputasi terbaru memerlukan kalibrasi model digital yang hati-hati agar mendapatkan alat yang andal untuk menyiapkan dan melaksanakan simulasi (Benni et al 2017). Selain itu, menurut Chen et al (2014)…”