# A Review of Progress and Hydrodynamic Design of Integrated Motor Pump-Jet Propulsion
## 4 Dynamic Coupling Technology  
### Dynamic Coupling between IMPs and Ship Hulls  
The interaction of a yacht's duct and hull was investigated by [PERSON] (2017) [39]. Figure 8 depicts the RDT installation, while Figure 8 depicts the water flow pattern (b). Between the propeller and the hull, this configuration created a flow vortex and negative pressure. \begin{table}
\begin{tabular}{p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt}} \hline \hline
**Year** & **Reference** & **Geometry of the Model** & **Parameter** & **Method/Experimental Method** & **Findings** \\ \hline
**2019** & [49] & Pump-jet propulsor & The rotor and stator thrust as well as the torque performance & The rotor and stator thrust as well as the torque performance & Mesh approach for flat-topped blades on a circular truncated cone and a tip leakage vortex model & Mesh approach for speed coefficients, and the addition of a tip vortex model improves the calculation results noticeably. \\  & & & The rotor and stator thrust as well as the torque performance & Mesh approach for flat-topped blades & The axial gap flow increases with the increase in the rotation speed. Changes in the fluid pattern within the gap result in changes in the differential pressure within the gap. \\  & & & The different speeds of the rotation and the advanced coefficient & Reynolds-averaged equation (RANS), and rotation of the rotor was simulated by moving reference frame (MRF) & The axial gap flow increases with the increase in the rotation speed. Changes in the fluid pattern within the gap result in changes in the differential pressure within the gap. \\ \hline
**2017** & [77] & Rim-driven propulsor & The different rapid and axial direction, speed, and pressure & Reynolds-averaged equation (RANS), and rotation of the rotor was simulated by moving reference frame (MRF) & The axial gap flow increases with the increase in the rotation speed. Changes in the fluid pattern within the gap result in changes in the differential pressure within the gap. \\ \hline
**2022** & [75] & The different gap ratios in a radial and axial direction, speed, and pressure & The different gap ratios in a radial and axial direction, speed, and pressure & The different gap ratios in a radial and axial direction, and the heat created in the motor dissipated fast in the gap flow. \\  & & & The effect of fluid viscosity in the gap zone & Combining the existing tip leakage vortex model and a suitable gap-flow model & The inclusion of the gap-flow model has the greatest impact on the duct of the pump-jet propulsor, bringing the duct’s hydrodynamic performance and pressure distribution more in line with the trend of the viscous flow calculation findings. \\  & & & Combining the existing tip leakage vortex model and a suitable gap-flow model & The gap-flow model has a minor effect on the overall hydrodynamic performance of the pump-jet propulsor’s calculation findings, and its determined value is only slightly raised. \\ \hline
**2021** & [81] & The effect of fluid viscosity in the gap zone, as well as the height of the gap gap & A low-order panel method based on velocity potential combining the existing tip leakage vortex model and a suitable gap-flow model & 1. The gap height should be 0.98–1.0 times the total gap height. \\  & & & A well as the height of the gap & Combining the existing tip leakage vortex model and a suitable gap-flow model & The flux coefficient (CQ) range of 0.8–0.84 was found to be suitable. \\  & & & & 0.8–0.84 was found to be suitable. gap-flow model & \\ \hline \hline \end{tabular}
\end{table} 
Table 5: _Cont._To optimize the structure and installation site of RDTs, it is critical to comprehend the interaction and nonlinear coupling between the wakefield, the RDT, and the hull. The efficiency of the system can be improved while minimizing sailing resistance by optimizing the RDT design, hull lines, and installation sites. To study the interactions between the hull and RDTs, [PERSON] et al.