Airflow temperature and humidity patterns in a screenhouse with a flat insect-proof screen roof and impermeable sloping walls – Computational fluid dynamics (CFD) results

2022 ◽  
Vol 214 ◽  
pp. 165-176
Author(s):  
Meir Teitel ◽  
Shay Ozer ◽  
Vered Mendelovich
2016 ◽  
Vol 36 (01) ◽  
pp. 64
Author(s):  
Anisum Anisum ◽  
Nursigit Bintoro ◽  
Sunarto Goenadi

One effort to optimize the temperature and humidity in the mushroom house during the dry season using evaporative cooler. This research was conducted two treatment variation which were assessed about distribution of temperature and humidity of air inside a mushroom house using Computational Fluid Dynamics (CFD) is the condition of building using natural ventilation and condition of building with water used evaporative cooler. Computational Fluid Dynamics (CFD) analysis was able to model the distributions of temperature and humidity, and air movement pattern inside of a mushroom house. The validation point of temperature distribution and humidity in the mushroom house has an error 0.70-2.62%. The results CFD analysis of temperature and humidity were able to reduced by about ±loC and ±5.1% for building with evaporative cooler used water. The indicated that buildings evaporative cooler used water able to reduced air temperature and increasing humidity in the mushroom houses.Keywords: Computational Fluid Dynamics (CFD), oyster, mushroom house,  evaporative cooler ABSTRAKSalah satu upaya untuk mengoptimalkan suhu dan kelembaban udara dalam rumah jamur pada musim kemarau dengan menggunakan evaporative cooler (pendingin penguap). Pada penelitian ini ada dua variasi perlakuan yang dikaji pendistribusian suhu dan kelembaban udara dalam rumah jamur dengan menggunakan Computational Fluid Dynamics (CFD), yaitu kondisi bangunan menggunakan ventilasi alamiah dan kondisi bangunan dengan pendingin penguap (evaporative cooler) menggunakan air. Analisis dengan Computational Fluid Dynamics (CFD) mampu memodelkan distribusi suhu dan kelembaban udara, serta pola pergerakan udara dalam rumah jamur. Nilai validasi distribusi suhu dan kelembaban udara dalam rumah jamur menunjukkan error 0,70 - 2,62%. Dari hasil analisis CFD suhu dan kelembaban udara mampu diturunkan sebesar ±1oC dan ±5,1% untuk bangunan dengan evaporative cooler menggunakan air. Hal ini menunjukkan bahwa bangunan dengan evaporative cooler menggunakan air mampu menurunkan suhu udara dan meningkatkan kelembaban udara dalam rumah jamur.Kata kunci: Computational Fluid Dynamics (CFD), rumah jamur (kumbung), evaporative cooler


2021 ◽  
Vol 13 (1) ◽  
pp. 17-31
Author(s):  
Cuauhtémoc Pérez-Vega ◽  
◽  
José Armando Ramírez-Arias ◽  
Irineo L. López-Cruz ◽  
Ramón Arteaga-Ramírez ◽  
...  

Introduction: Medium and low technology greenhouses use natural ventilation as a method of temperature and humidity control. However, at certain times of the year, this is insufficient to extract excess heat inside the greenhouse, so devices such as hydrophanes (humidifiers) have been implemented to reduce the temperature. It is necessary to know the behavior of temperature and humidity, since both factors influence the development of crops and, therefore, their yield. Objective: To develop a computational fluid dynamics (CFD) model of a naturally ventilated zenithal greenhouse equipped with hydrophanes to understand the spatial and temporal distribution of temperature and humidity inside the greenhouse. Methodology: The experiment was carried out in a greenhouse equipped with hydrophanes and grown with bell pepper. Temperature and humidity measurements were performed from March 7 to 25, 2014. The ANSYS Workbench program was used for the 3D CFD modeling. Results: The CFD model satisfactorily described the temperature and humidity distribution of the greenhouse, with an error of 0.11 to 3.43 °C for temperature, and 0.44 to 10.80 % for humidity. Limitations of the study: Numerical modeling using CFD is inadequate to model the temporality of the variables. Originality: There are few studies that model humidity behavior with CFD and the use of hydrophanes in Mexico. Conclusions: The CFD model allowed visualizing the distribution of temperature and air humidity inside the greenhouse.


1996 ◽  
Vol 33 (9) ◽  
pp. 163-170 ◽  
Author(s):  
Virginia R. Stovin ◽  
Adrian J. Saul

Research was undertaken in order to identify possible methodologies for the prediction of sedimentation in storage chambers based on computational fluid dynamics (CFD). The Fluent CFD software was used to establish a numerical model of the flow field, on which further analysis was undertaken. Sedimentation was estimated from the simulated flow fields by two different methods. The first approach used the simulation to predict the bed shear stress distribution, with deposition being assumed for areas where the bed shear stress fell below a critical value (τcd). The value of τcd had previously been determined in the laboratory. Efficiency was then calculated as a function of the proportion of the chamber bed for which deposition had been predicted. The second method used the particle tracking facility in Fluent and efficiency was calculated from the proportion of particles that remained within the chamber. The results from the two techniques for efficiency are compared to data collected in a laboratory chamber. Three further simulations were then undertaken in order to investigate the influence of length to breadth ratio on chamber performance. The methodology presented here could be applied to complex geometries and full scale installations.


2021 ◽  
Vol 54 ◽  
pp. 102207
Author(s):  
Cristian Inostroza ◽  
Alessandro Solimeno ◽  
Joan García ◽  
José M. Fernández-Sevilla ◽  
F. Gabriel Acién

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 332
Author(s):  
Hong Yong Sohn ◽  
De-Qiu Fan ◽  
Amr Abdelghany

The development of a novel ironmaking technology based on fine iron ore concentrate in a flash reactor is summarized. The design of potential industrial reactors for flash ironmaking based on the computational fluid dynamics technique is described. Overall, this simulation work has shown that the size of the reactor used in the novel flash ironmaking technology (FIT) can be quite reasonable vis-à-vis the blast furnaces. A flash reactor of 12 m diameter and 35 m height with a single burner operating at atmospheric pressure would produce 1.0 million tons of iron per year. The height can be further reduced by either using multiple burners, preheating the feed gas, or both. The computational fluid dynamics (CFD)-based design of potential industrial reactors for flash ironmaking pointed to a number of features that should be incorporated. The flow field should be designed in such a way that a larger portion of the reactor is used for the reduction reaction but at the same time excessive collision of particles with the wall must be avoided. Further, a large diameter-to-height ratio that still allows a high reduction degree should be used from the viewpoint of decreased heat loss. This may require the incorporation of multiple burners and solid feeding ports.


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