## 4 Conclusions  
In this paper, aiming at the vibration isolation requirements of airborne optical equipment, a MRE vibration isolator is designed by using the advantages of real-time tracking/away from external excitation frequency of MRE application devices, and its material and magnetic circuit are analyzed. Finally, the structural parameters are optimized by the finite element method and COMSOL simulation software. The main conclusions are as follows:  
Aiming at the design and research of a double-layer water injection well and one graded water distributor, a set of single motor-driven water distributors is designed to realize underground two-layer water injection, and the key structures of the water distributor are simulated by fluid and dynamics. The main research conclusions are as follows:  
1. Based on the performance advantages of MRE application devices, the structural design of the MRE isolator is completed. Based on the designed structural form, its materials and magnetic circuits are analyzed, and its internal materials are optimized. The maximum magnetic field in the MRE region is realized under the same energy input, and the working efficiency of the MRE isolator is improved.
2. The structural parameters of the MRE isolator were optimized by the finite element method and COMSOL simulation software. The optimal solution to meet the comprehensive index of the optimal vibration isolation performance of the MRE isolator is obtained as \(r_{1}\) 15.0 mm, \(r_{4}\) 36.0 mm, and \(h_{3}\) 53.5 mm, and the average magnetic induction intensity at the MRE reaches the maximum value of about 417.46 mT at 3 A current, which can improve its magnetic control performance and reduce the energy consumption, volume, and weight of the device.  
The MRE isolator designed in this paper meets the vibration isolation requirements of airborne optical equipment. The simulation analysis results are reasonable. It has good semi-active vibration reduction/isolation performance. The structure is simple and reliable. The MRE device has good stability and applicability. It can achieve high-precision vibration reduction and stabilization of airborne optical equipment in a wide frequency range and improve the stability and accuracy of optical system tracking and aiming. The design idea of this paper can provide effective theoretical support for the engineering application of MRE isolators in the field of vibration isolation of airborne equipment. However, this paper only uses theoretical analysis and simulation optimization to complete the design of the MRE isolator, and the results can be further studied and verified by physical objects.  
Conceptualization, D.Y. and S.W.; methodology, Y.Z.; software, H.L.; investigation, S.L.; writing--review and editing, H.F. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Figure 10: Structural sectional view of the MRE isolator after parameter optimization.  
**Data Availability Statement:** The data mentioned in this article are all genuine and available, and any data not provided is confidential.  
**Acknowledgments:** This research is supported by the Southwest Institute of Technical Physics.  
**Conflicts of Interest:** The authors declare no conflict of interest.