Bilal CEMEK, Aslıhan ATİŞ, Erdem KÜÇÜKTOPÇU

Evaluation of temperature distribution in different greenhouse models using computational fluid dynamics (CFD)

Hava giriş ve çıkış açıklıklarının alanları, konumları, giriş ve çıkış açıklıkları arası yükseklik farkı, rüzgar yönü, sera geometrisi ve serada yetiştirilen bitki çeşidi gibi birçok faktör havalandırma sisteminin planlanmasında etkili olmaktadır. Bu çalışmada havalandırma sistemlerinin etkisini değerlendirebilmek amacıyla farklı yan duvar yüksekliğine, havalandırma giriş çıkış açıklıklarına ve sera çatı şekillerine sahip beş farklı özellikte plastik sera kullanılmış ve bu sera modelleri ile bölgede kullanılan tipik sera modeli karşılaştırılmıştır. Çalışmada kullanılan tüm sera modellerinin iç çevre koşulları (hava akış hızı ve sıcaklık dağılımları) ve hava değişim oranları Hesaplamalı Akışkanlar Dinamiği (HAD) ile değerlendirilmiştir. Simülasyonlardaki tüm koşullar için dış hava hızı 0.5, 1 ve 2 ms-1 olarak belirlenmiştir. Sera içi etkili havalandırma sisteminin çözümünde HAD’nin “FLUENT” yazılım programından yararlanılmıştır. Çözümde ise türbülans modeli olarak k-ɛ Renormalization Group (RNG) türbülans modeli kullanılmıştır

Hesaplamalı akışkanlar dinamiği (HAD) kullanılarak farklı sera modellerindeki sıcaklık dağılımının değerlendirilmesi

Areas of air inlet and outlet openings, orientation of openings, height difference between air inlet and outlet openings, wind direction, greenhouse geometry, and type of plant grown are among the many factors that should be taken into consideration in designing an effective ventilation system for greenhouses. In this study, five different model plastic greenhouses with different sidewall heights, air inlet and outlet opening areas and roof shapes were used to evaluate the ventilation efficiencies and they were compared with a conventional type of the region. A computational fluid dynamics (CFD) program was used to evaluate the behavior of the internal environment (internal flow rate and temperature distributions) and natural ventilation rates for all model greenhouses and a conventional greenhouse involved in the study. External wind speeds of 0.5, 1, and 2 ms-1 were used in the simulations for all conditions. The results of simulations and experimental studies were evaluated and used for recommendation of a better greenhouse model for this region. CFD software “FLUENT” was used to determine the effectiveness of greenhouse ventilation system and k-ɛ Renormalization Group (RNG) turbulence model was used in solutions.

Keywords:

Computational fluid dynamics Natural ventilation, Greenhouse, Samsun,

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