Comparation of inner climatic factors measured and simulated by means of computational fluid dynamics in naturally ventilated greenhouses

In this study, the comparation of measured inner climatic factors with simulated values of single greenhouses having different direction and window openness conditions was aimed. Therefore greenhouses located in Western Mediterranean Agricultural Research Institute in Antalya were used as material. For each of the different sizes gable roofed single glasshouse in the study area, observations and measurements were made and structural features and dimensions of each greenhouse were determined. Measurement values were recorded every 2 hours between of 08:00-18:00 for each greenhouses by means of temperature, humidity and velocity dataloggers located in different places in greenhouses. Measurements were made under 6 different window openness condition ranging from 45o to 90o in greenhouses with and without plants and directed in North-South and East-West. Afterwards, greenhouses used as material were drawn in one to one properties using SolidWorks package software which is working by means of Computational Fluid Dynamics (CFD) method. Using temperature, humidity and wind speed limits values measured and recorded in the ambient conditions and some structural and physical properties of greenhouses, climatic conditions inside greenhouses were simulated. As a result, the temperature distribution inside the greenhouse increase depending on the external environment was observed. This increase varies according to greenhouse direction, window openness degree and cultivation environment. Temperature distribution inside greenhouse is almost the same level with the external environment at the edges of window; this value increased a little more in greenhouse center and reached its maximum value at the ridge of a roof level. A good agreement as high as 93% between measured and simulated temperature values were found. Humidity distribution reduced depending on the external environment. This decrease varies according to greenhouse direction, window openness degree and cultivation environment. Humidity distribution inside greenhouse is almost same level with the external environment at the edges of window; this value reduced a little more in greenhouse center and reached its minimum value at the ridge of a roof level. A good agreement as high as 90% between measured and simulated humidity values were found. Velocity distribution inside the greenhouse agreed well with external environment. It was observed that the velocity distribution inside greenhouse is different depending on greenhouse direction, window openness degree and cultivation environment. A good agreement as high as 80% between measured and simulated velocity values were found. In general, an average agreement about 88% between measured and simulated values of temperature, humidity and wind speed inside greenhouses were determined as a result of study.