In order to explore the changes in biochemical components and mechanical properties of cucumber seedlings with dwarfing characteristics under airflow disturbance treatment, ‘Jinyou No. 1’ cucumber seedlings were used as experimental materials and the split-plot design was used. The cucumber seedlings were treated with airflow disturbance with two airflow temperatures of 25 ± 5 °C and 35 ± 5 °C as the main factors and four airflow velocities of 1, 3, 6 and 9 m/s as the secondary factors. At the same time, cucumber seedlings without airflow disturbance were used as controls to study the effects of airflow temperature and velocity on the biochemical components and mechanical properties of cucumber seedling stems. The results showed that with the increase in airflow velocity, the content of the stems’ biochemical components increased to varying degrees, and the bending load, shear load, elastic modulus, bending strength and shear strength of the seedling stems also increased. Under the same airflow velocity, the biochemical component content and the accepted load of seedlings under the 25 ± 5 °C airflow temperature treatment were larger than those under the 35 ± 5 °C airflow greenhouse treatment, but the elastic modulus, bending strength and shear strength of seedlings under the 25 ± 5 °C airflow temperature treatment were lesser than those under the 35 ± 5 °C airflow temperature treatment. Using the grey relational analysis method, the correlation degree between the biochemical components of the stem and the mechanical properties of the stem was different. The correlation degree between the biochemical components of the seedling stem and the mechanical properties under different airflow temperature treatments was significant. The correlation degree between the biochemical components of the seedling stem and the mechanical properties under different airflow velocity treatments was greater than 0.60, indicating that the biochemical components of the seedling stem under airflow velocity treatments had a greater influence on the mechanical properties. In summary, airflow disturbance significantly affected the biochemical components and mechanical properties of cucumber seedlings. The biochemical components and mechanical properties of seedlings were negatively correlated with airflow temperature and positively correlated with airflow velocity. With a decrease in airflow temperature and an increase in airflow velocity, the biochemical components and mechanical properties of seedlings increased.

Sucrose is the main constituent of assimilation transport from source to sink. In order to study the transport mechanism of sucrose, the sucrose at stem was taken as a research object and the sucrose flow field in tomato stem was analyzed using CFD ANSYS FLUENT simulation. The results showed that the sucrose pressure distribution was lower at bottom node and higher at middle node. The velocity of sucrose at different nodes was higher at the bottom node and lower at middle node and assimilation flow direction of the first, second, and third leaf from the bottom was towards the roots. The result of verification experiment showed that sucrose content measured at different nodes was higher at middle node than that of bottom node. Results of this study confirmed that ANASYS FLUENT can better simulate sucrose migration in greenhouse tomato stem. This study provides a new method for studying the partitioning mechanism of tomato assimilates in greenhouse. Keywords: greenhouse tomato, sucrose flow field, computational fluent dynamic, rule of distribution DOI: 10.25165/j.ijabe.20221501.6061 Citation: Ni J H, Dong J T, Ullah I, Mao H P. CFD simulation of sucrose flow field in the stem of greenhouse tomato seedling. Int J Agric & Biol Eng, 2022; 15(1): 111–115.