Research On CFD Temperature Simulation Model Of Solar Greenhouse Based On Tomato Group Effect

Greenhouse environmental regulation and control is the main means to improve the crop environment.The greenhouse microclimate simulation model can quantitatively describe the changes of various environmental factors and their relationship with time,becoming a powerful tool for optimizing and regulating the greenhouse environment.However,in the research of CFD simulation modeling at home and abroad,some scholars ignore the impact of crops on the environment,and some scholars consider it,but they all regard it as a stable porous medium structure,it produces certain errors.Therefore,establish a corresponding experiment for the simulation model,study the influence of tomato populations under different cultivation modes,different biomass and different external conditions on the thermal environment inside the solar greenhouse,find out the physical parameters of the crop foundation,and use CFD technology for simulation verification is necessary to improve the accuracy of the model.The main results are as follows:1.The effect of different treatment tomato populations on the temperature of the solar greenhouse is directly proportional to the biomass of the population and has nothing to do with the colonization model;the difference between day and night is also proportional to the biomass.The difference between the temperature of the tomato population between each treatment and the temperature of the empty greenhouse increased with the increase of the biomass of the tomato plant,the plant population was 160 plants,and the tomato population with a planting density of 4.44 plants/m2 was affected by the temperature of the solar greenhouse during the fruiting period The influence is greatest,and the temperature difference is 2.09°C.2.Under high-temperature and strong-light weather conditions,tomato crops have more influence on room temperature than low-temperature and low-light weather.When the outside temperature is consistent,the sunny day can increase by 1.36 °C;when the light intensity is consistent,the outside temperature is higher than the low temperature,the temperature difference increases by 0.69 °C.3.Based on experimental tests,Solidworks software is used to construct a proportional geometric model,Mesh software is used to discretize the physical model of the greenhouse,and the environment is simulated under Fluent software.The indoor and outdoor measured data are used to set the initial conditions and boundary conditions of the simulation model.The appropriate governor is used to solve the differential governing equations of the microclimate model.The CFD numerical method was used to build a simulation model of the impact of tomato population on the greenhouse,and the specific analysis of the greenhouse room temperature change law under different biomass and different working conditions in the single-row planting mode.The actual measured data and simulation data are compared and analyzed.The results of simulation verification are: the overall average relative errors between the experimental measured data of the empty greenhouse,80 plants,120 plants,and 160 plants and the simulated data are 10.65%,9.09%,8.56%,and 3.56%,verified the validity of the room temperature prediction model,and provided a theoretical basis for exploring the greenhouse temperature prediction of tomato populations under different planting conditions.