| Rapeseed lodging seriously hinders the improvement of rape yield and the development of agriculture-related industries in China.Rapeseed lodging is not only related to varieties,but also one of the key factors to induce rape lodging.Exploring the effect of rape branch structure on plant lodging resistance and obtaining an ideal plant type structure with strong wind resistance can provide theoretical support for the cultivation and breeding of rape lodging resistance ideal plant type.In this study,the number,angle,length of stem segment and the height of the first effective branch(the height of the first effective branch from the root up to the ground)were used as indicators to design different rape strains with different plant structures based on rape growth habit.The three-dimensional reconstruction and inverse modeling techniques were used to complete the three-dimensional reconstruction of the solid model of rapeseed,and the model was adjusted to meet the experimental design of rapeseed model.The change of rapeseed branch layout was analyzed from the perspective of rapeseed canopy porosity and the intrinsic effect of the change of rapeseed branch layout on the change of rapeseed wind speed.A free-jet wind tunnel test platform was built for rapeseed plant failure tests to determine the wind speed of different rapeseed strains and to verify the results of the simulation tests,and finally to obtain the ideal rapeseed strain for failure resistance.The main research contents and conclusions are as follows:(1)The technical principles of motion recovery structure algorithm are used to obtain two-dimensional pictures of rapeseed with 360 ° perspective for rapeseed rapeseed during the corner fruit period.Use Visuals FM to realize the reconstruction of two-dimensional images to 3D cloud models;complete filtering through Cloud Com Pare to reduce noise;then use Geomagic Studio to achieve rapeseed plants from point cloudization to slicitization,and eventually processed;finally use UNIGRAPHICS NX to achieve Regarding the adjustment of the first-level branches structure of the model,the number of branches,the length of the stem section,the angle and the first effective branches height of the first-level branches,the angle,and the first effective branches are the regulatory parameters,design the plant type test scheme,and obtain the three-dimensional model of the rapeseed three-dimensional models of different structures In the agricultural parameters such as the height of the plant,the length of the branches,the length of the branches,and the angle of the angle,the reconstruction accuracy of the rape model is verified.Model reconstruction accuracy and subsequent simulation test requirements.(2)Based on the theory of fluid solid coupling,ANSYS Workbench software was applied to simulate the fluid solid coupling between rapeseed and natural wind using a three-dimensional reconstructed multi structure rapeseed model as the experimental object.Through single factor simulation experiments,the influence of the layout of the first level branch structure on the lodging resistance of rapeseed plants was explored,and a regression prediction model was established based on response surface analysis to ultimately determine the optimal spatial layout of the first level branch.The research results indicate that the agronomic parameters of the first branch of rapeseed plants have a significant impact on plant lodging(p<0.05).The research results indicate that the agronomic parameters of the first branch of rapeseed plants have a significant impact on plant lodging(p<0.05).As the number of primary branches decreases,the length of stem segments of primary branches decreases,the angle of primary branches decreases,the height of the first effective branch decreases,and the lodging resistance of rapeseed plants increases.The ideal plant type structure for rapeseed lodging resistance is as follows: the number of first level branches is 10,the relative length of the stem segment of the first level branch is 0.2,the angle of the first level branch is 25 °,and the relative height of the first effective branch is 0.15.At this time,the predicted maximum lodging wind speed is 17.37m/s,and the maximum lodging wind speed of the optimal structure is increased by 33.8%.(3)The 5-point sample method is adopted to select the angle period Huabi 62 rapeseed,hold it on the free shooting wind tunnel test platform,and verify the results of the simulation test.The simulation wind speed of the wind tunnel can reach the wind speed requirements(wind speed 10m/s-20m/s)with the wind speed of rapeseed(the stems are over 45 °).The design of the single factor test,the method of recording the video of the mobile phone,the wind speed and the dynamic stability of the plant,and the wind speed displayed on the wind speed instrument on the wind speed instrument when the rapeseed stems reaches 45 ° inverted.The results show that the test results of the number of primers,the length of the stem section,angle and the height of the first effective branches are consistent with the simulation results. |
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