Effect of material ageing and dirt on the behaviour of greenhouse insect-proof screens
The present work examines the variations in the aerodynamic characteristics of four insect-proof screens by means of wind tunnel tests and digital image processing. The tested insect-proof screens were examined in three different conditions: (i) in their new, unused state; (ii) under conditions of a...
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| Format: | info:eu-repo/semantics/article |
| Language: | English |
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CONSEJO SUPERIOR INVESTIGACIONES CIENTIFICAS-CSIC
2023
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| Online Access: | http://hdl.handle.net/10835/14698 https://doi.org/10.5424/sjar/2018164-11711 |
| _version_ | 1789406296670208000 |
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| author | López Martínez, Alejandro Valera Martínez, Diego Luis Molina Aiz, Francisco Domingo Peña Fernández, Ana Araceli Espinoza Ramos, Karlos |
| author_facet | López Martínez, Alejandro Valera Martínez, Diego Luis Molina Aiz, Francisco Domingo Peña Fernández, Ana Araceli Espinoza Ramos, Karlos |
| author_sort | López Martínez, Alejandro |
| collection | DSpace |
| description | The present work examines the variations in the aerodynamic characteristics of four insect-proof screens by means of wind tunnel tests and digital image processing. The tested insect-proof screens were examined in three different conditions: (i) in their new, unused state; (ii) under conditions of accumulated dust and dirt after a period of 3 to 4 years of use; and (iii) under clean conditions after a period of 3 to 4 years of use and a cleaning treatment with high-pressure water. The deterioration of the screens caused the mesh to become less tense, therefore increasing its thickness and improving its aerodynamic behaviour despite a slight increase of the thread diameter and a subsequent decrease of the 2-dimensional porosity. The pressure drop coefficient, Fφ, of the used but clean screens was 1.5% to 8.8% lower (for u=1.0 m/s) than that of the new ones, thus increasing the discharge coefficient, Cd,φ, by between 0.8% and 4.8% as a result of the presence of the screens. On the other hand, comparison of the used screens in their clean and unclean states showed that the accumulation of dirt has a major bearing on their aerodynamic characteristics: Fφ increased by between 16.5% and 61.2% (for u=1.0 m/s) for the unclean screens, resulting in a Cd,φ reduction of between 7.5% and 21.3% and therefore a lower natural ventilation capacity of the greenhouse. A regular cleaning treatment of the insect-proof screens is a simple measure that improves the natural ventilation capacity of the greenhouse. |
| format | info:eu-repo/semantics/article |
| id | oai:repositorio.ual.es:10835-14698 |
| institution | Universidad de Cuenca |
| language | English |
| publishDate | 2023 |
| publisher | CONSEJO SUPERIOR INVESTIGACIONES CIENTIFICAS-CSIC |
| record_format | dspace |
| spelling | oai:repositorio.ual.es:10835-146982023-11-28T12:01:17Z Effect of material ageing and dirt on the behaviour of greenhouse insect-proof screens López Martínez, Alejandro Valera Martínez, Diego Luis Molina Aiz, Francisco Domingo Peña Fernández, Ana Araceli Espinoza Ramos, Karlos The present work examines the variations in the aerodynamic characteristics of four insect-proof screens by means of wind tunnel tests and digital image processing. The tested insect-proof screens were examined in three different conditions: (i) in their new, unused state; (ii) under conditions of accumulated dust and dirt after a period of 3 to 4 years of use; and (iii) under clean conditions after a period of 3 to 4 years of use and a cleaning treatment with high-pressure water. The deterioration of the screens caused the mesh to become less tense, therefore increasing its thickness and improving its aerodynamic behaviour despite a slight increase of the thread diameter and a subsequent decrease of the 2-dimensional porosity. The pressure drop coefficient, Fφ, of the used but clean screens was 1.5% to 8.8% lower (for u=1.0 m/s) than that of the new ones, thus increasing the discharge coefficient, Cd,φ, by between 0.8% and 4.8% as a result of the presence of the screens. On the other hand, comparison of the used screens in their clean and unclean states showed that the accumulation of dirt has a major bearing on their aerodynamic characteristics: Fφ increased by between 16.5% and 61.2% (for u=1.0 m/s) for the unclean screens, resulting in a Cd,φ reduction of between 7.5% and 21.3% and therefore a lower natural ventilation capacity of the greenhouse. A regular cleaning treatment of the insect-proof screens is a simple measure that improves the natural ventilation capacity of the greenhouse. 2023-11-28T12:01:17Z 2023-11-28T12:01:17Z 2019-01-08 info:eu-repo/semantics/article 1695-971X 2171-9292 http://hdl.handle.net/10835/14698 https://doi.org/10.5424/sjar/2018164-11711 en info:eu-repo/semantics/openAccess CONSEJO SUPERIOR INVESTIGACIONES CIENTIFICAS-CSIC |
| spellingShingle | López Martínez, Alejandro Valera Martínez, Diego Luis Molina Aiz, Francisco Domingo Peña Fernández, Ana Araceli Espinoza Ramos, Karlos Effect of material ageing and dirt on the behaviour of greenhouse insect-proof screens |
| title | Effect of material ageing and dirt on the behaviour of greenhouse insect-proof screens |
| title_full | Effect of material ageing and dirt on the behaviour of greenhouse insect-proof screens |
| title_fullStr | Effect of material ageing and dirt on the behaviour of greenhouse insect-proof screens |
| title_full_unstemmed | Effect of material ageing and dirt on the behaviour of greenhouse insect-proof screens |
| title_short | Effect of material ageing and dirt on the behaviour of greenhouse insect-proof screens |
| title_sort | effect of material ageing and dirt on the behaviour of greenhouse insect-proof screens |
| url | http://hdl.handle.net/10835/14698 https://doi.org/10.5424/sjar/2018164-11711 |
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