CFD Numerical Simulation And Application Of Narrows Rice Seedling Greenhouse Environment

Northern cold region agricultural growing season is short, less accumulated years of activity, is part of growing rice seedling essential. Temperature and humidity and other factors are important indicators of the impact of the rate of seedling seedlings, therefore, to ensure uniform distribution of temperature and humidity seedling field has practical significance. In this paper, rice seedling greenhouse for the study, the use of computational fluid dynamics on the temperature and humidity inside the greenhouse seedling field and flow field simulation, verification and comparison of predictions. Optimize the structure of the shutter, and propose seedling greenhouse ventilation control measures under different external conditions.(1) Combined with CFD theoretical knowledge and practical model of seedling greenhouses, a soil- plant- air- envelope mathematical model to analyze the thermal mass exchange between the various environmental factors. Gambit software application for rice seedling greenhouse physical modeling, select Realizable model as equations, deal with near-wall low Re flows through the wall function method, the use of solar ray tracing simulation of sunlight, take DO model shed heat radiation effective to solve, Rice seedlings part of porous medium model representation using component model to solve humidity inside the greenhouse.(2) On the basis of field measurement data set boundary conditions, respectively, and there is no rice seedling rice seedling rice seedling greenhouse internal temperature and humidity and air velocity field distribution is simulated, and the simulated values and the measured values of temperature and humidity testing.(3) On the seedling greenhouses shutter structure parameter analysis and optimization. Respectively, after the opening of shutter length and structure parameters are optimized to optimize the distribution of temperature, humidity and airflow inside greenhouses significantly compared to the previous field uniform to achieve optimization purposes, to provide a good environment for the growth of rice seedlings.(4) In order to meet a good environment for the growth of seedlings, the study based on the actual production requirements, through the greenhouse seedling internal environment numerical simulation analysis, optimum ventilation area under different external environment seedling greenhouse, rice seedlings grown to provide effective control measures to improve seedling rate.In this paper, the use of computational fluid dynamics in Cold rice seedling greenhouse environment is simulated and experimental data through comparative study of temperature and humidity, optimizing the shutter structure parameters. The results show that: the use of CFD simulation greenhouse temperature and humidity field and flow field feasible, optimized shutter parameter greenhouse temperature, humidity and gas distribution improved. By adjusting the ventilation area for the growth of seedlings to provide effective control measures to improve the quality of rice seedling growth it is of great significance.