Computational analysis of ventilation in greenhouses at zero- and low-wind speeds.

Abstract A systematic analysis of the natural ventilation process in greenhouses at no-wind and low-wind-speed conditions was performed with the use of Computational Fluid Dynamics (CFD). The validity of this approach was first checked with success by comparing the numerical results with experimental data obtained from the literature. Numerical predictions of the ventilation efficiency of typical Mediterranean-type greenhouses were obtained for various ventilator configurations. These computer simulations were based on a realistic representation of the heat sources and the boundary conditions related to the problem. The contribution of specific ventilators to the greenhouse air renewal was analysed. The importance of side-wall ventilators for an efficient thermally driven ventilation (‘buoyancy effect’) was confirmed. It was demonstrated that CFD is a powerful tool for developing improved designs with respect to ventilation efficiency.

[1]  G. Bot.  Greenhouse climate: from physical processes to a dynamic model , 1983 .

[2]  G. Papadakis,et al.  Measurement and Analysis of Air Exchange Rates in a Greenhouse with Continuous Roof and Side Openings , 1996 .

[3]  H. F. DeZwart.  Determination of Direct Transmission of a Multispan Greenhouse Using Vector Algebra , 1993 .

[4]  S. Patankar.  Numerical Heat Transfer and Fluid Flow , 2018, Lecture Notes in Mechanical Engineering.

[5]  George Papadakis,et al.  Wind Induced Air Exchange Rates in a Greenhouse Tunnel with Continuous Side Openings , 1996 .

[6]  B. Launder,et al.  The numerical computation of turbulent flows , 1990 .

[7]  Francis H. Harlow,et al.  TRANSPORT OF TURBULENCE ENERGY DECAY RATE. , 1968 .

[8]  Pietro Picuno,et al.  Analysis of the efficiency of greenhouse ventilation using computational fluid dynamics , 1997 .

[9]  T. Takakura,et al.  Wind tunnel testing on airflow and temperature distribution of a naturally ventilated greenhouse. , 1984 .

[10]  V. V. Baturin.  Fundamentals of industrial ventilation , 1972 .

[11]  A. J. Udink ten Cate,et al.  A practical tracer gas method to determine ventilation in greenhouses , 1985 .

[12]  D. L. Critten,et al.  Light transmission losses due to structural members in multispan greenhouses under diffuse skylight conditions , 1987 .

[13]  G. Papadakis,et al.  Experimental investigation and modelling of heat and mass transfer between a tomato crop and the greenhouse environment , 1994 .

[14]  M. Mermier,et al.  Mesures et modélisation de la résistance stomatique foliaire et de la transpiration d'un couvert de tomates de serre , 1991 .

[15]  J. A. Stoffers,et al.  Natural convection heat transfer in covered plant canopies , 1975 .

[16]  G. Wigley,et al.  Heat transport coefficients for constant energy flux models of broad leaves , 1974 .

[17]  de H.F. Zwart,et al.  Analyzing energy-saving options in greenhouse cultivation using a simulation model , 1996 .

[18]  X. Yang,et al.  The Microclimate and Transpiration of a Greenhouse Cucumber Crop , 1989 .

[19]  C. Stanghellini,et al.  Transpiration of greenhouse crops : an aid to climate management , 1987 .

[20]  W. Swinbank.  Long‐wave radiation from clear skies , 1963 .

[21]  George Papadakis,et al.  Soil energy balance analysis of a solar greenhouse , 1989 .