# Design and Test of Vertical Axis Rotating Cutters for Cutting Corn Roots and Crown
## 3 Results and Discussion
### Consistency of the Results in the Field and Simulation Tests  
Under the condition of the forward speed of 1.01 m\(\cdot\)s\({}^{-1}\) and the rotational speed of the cutter shaft of 460 r\(\cdot\)min\({}^{-1}\), the consistency of the results in the field and simulation tests results was analyzed, and the results are shown in Figure 10. The power consumption of the device measured in the field test was 6.9 kW, and the error relating to the results in the simulation was 0.1 kW. The small error effectively proved the effectiveness and reliability of the developed torque measurement system in the field test and also verified the accuracy of the power consumption calculation of the device based on the cutter shaft torque in the  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Source** & **Sum of Squares** & **df** & **Mean Square** & **F Value** & \(p\)**-Value Prob \textgreater{} F** \\ \hline Model & 116.31 & 24 & 4.85 & 85,736.39 & \textless{}0.0001 \\ A & 76.57 & 4 & 19.14 & 3.387 \(\times\) 10\({}^{5}\) & \textless{}0.0001 \\ B & 35.88 & 4 & 8.97 & 1.587 \(\times\) 10\({}^{5}\) & \textless{}0.0001 \\ AB & 3.86 & 16 & 0.24 & 4270.63 & \textless{}0.0001 \\ Pure Error & 2.826 \(\times\) 10\({}^{-3}\) & 50 & 5.652 \(\times\) 10\({}^{-5}\) & & \\ Cor Total & 116.31 & 74 & & & \\ \hline \hline \end{tabular}
\end{table}
Table 4: The mathematical model relating forward speed and rotational speed of the cutter shaft to the power consumption of the device.  
Figure 9: Effect of different factors on the power consumption of the device.  
simulation test. Furthermore, it was also proved that the simulation accurately captured the interaction forces among the cutters, root-crown, and soil, providing strong support for subsequent research. The qualified rate of root-crown length in the field test was 94.18%, and the error relating to the results in the simulation test was 0.1%. The comparison revealed that the morphology of the root-crown after cutting was highly consistent between the field test and simulation test, which proved the feasibility of employing the Bonding model and the JKR model to simulate the effect of cutting the root-crown in the simulation. The error in the rate of soil disturbance between the field and simulation tests was only 1.59%. In the two tests, the ridge after disturbing showed the shape change from \"M\" to \"A\" along the forward direction of the device, which further validated the applicability and accuracy of the JKR model in simulating the interaction between cutters and soil. When the device moved forward, the soil in the deep soil layer was disturbed by the involute curve edge that had the maximum turning radius. The soil would be thrown from the middle of the ridge outwards. In the early stage of cutting roots, this action results in an \"M\"-shaped ridge. During the forward movement of the device and the continuous rotation of the cutter shaft, the Archimedean-spiral edge and sine curve edge began to disturb the middle soil layer and the surface soil layer, respectively. The soil within rotation areas of the two types of edges would be thrown from the rotation center of the cutter shaft. Consequently, the \"A\"-shaped ridge evolved in the latter stage of cutting roots. We discovered that this particular shape of the ridge was driven by the multi-curve cutter. Importantly, this shape corresponded to the lower rate of soil disturbance. This minimal disturbance is beneficial for protecting the soil structure and fertility, maintaining soil biodiversity, and enhancing the efficiency of water resource utilization.