## 3 Results  
### Model Validation  
#### 3.1.1 Electromagnetic Field Validation  
To validate the correctness of the proposed method, the electromagnetic field distribution at different times and the port reflection coefficient computed by the proposed method are compared with the computation results of the conventional discrete position method. The turntable lifting speed is \(v_{p}=0.3\) cm/s, the angular velocity of rotation is \(\omega=\pi/10\) rad/s and the electric field distribution after 10 s motion is shown in Figure 7. As shown in Figure 7a, \(h_{0}\) is the initial height equals 10 mm, the rotation angle of the sample is \(\pi\) and the lifting height \(h\) is equal to 3 cm. The electric field plane shown in Figure 7a is the center section plane of the sample, and the center of the sample is located at (0.025, 0) (Unit: m). A position sketch of the sample is shown in Figure 7d. Clearly, the electric field outside the transform optical region computed by the proposed method is consistent with that at the discrete position. Inside the two transform optical regions, due to the medium, the parameters change into time-varying tensor form, and the electric field of region 1 and region 2 rotates with an angle, which, as we know from Equation (22), is \(\pi/2\). Compared to the electric distribution at a discrete position, the electric field computed by the proposed method rotates with an angle of \(\pi\), and the electric field distribution of the two inside the potato matches very well. Moreover, in Figure 7a, the discrete position shows the positions of the elements after movement and the modeling situation, while the positions of all elements inside the microwave cavity remain static; that is to say, when using the proposed method to compute, the mesh is only needed once. Furthermore, this method eliminates the correlation between the electric field distribution and the position of the physical domain but becomes a functional form related to the coordinates and time. The results show that the proposed method is feasible. Figure 7: **(a)** A 2D diagram of the proposed method and the discrete position after 10 s of motion (unit: mm): **(I)** is the computation model and electric field distribution diagram of proposed method; **(II)** is the computation model and electric field distribution diagram of discrete position method. **(b)** The electric field distribution inside the cavity of the proposed method and the discrete position after 10 s of motion. **(c)** The electric field distribution in the potato’s central section of the proposed method and discrete position after 10 s of motion. **(d)** Top view of sample’s initial position. To further verify the accuracy of the proposed method, the electric field distribution in the central section of the sample at different times is shown in Figure 8. In Figure 8a, the electric field distribution was computed at discrete positions, and Figure 8b is the electric field distribution computed by the proposed method. It should be noted that with the change of time, the discrete positions method needs to reconstruct the model of different time steps and redivide the elements. However, the proposed method only needs to divide the elements once. Moreover, in Figure 8, the electric field distribution computed by the proposed method is in good agreement with the discrete method. Meanwhile, the comparison of port reflection coefficient \(S_{11}\) computed by the proposed method and at discrete positions at different times is also plotted, which is shown in Figure 9. The result shows that the \(S_{11}\) computed by the proposed method fits well with those computed by the discrete positions. These results show that the electric field distribution of the microwave cavity with moving elements can be accurately computed by the proposed method. Figure 8: The electric distribution at the central section of the sample (potato) at different times with (**a**) discrete positions and (**b**) the proposed method.