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In order to study the inter flow of magnetic drive pump, the total flow field of magnetic drive pump was simulated with CFD software based on SST $k$ - $\omega $ turbulence model, and the flow fields distribution rules of cooling channel were analyzed under different working conditions. The numerical results show that the internal flow of magnetic drive pump was disorganized under small flow condition, then the inter flow becomes gradually smooth with the increase in flux, at the same time, the area with low speed near the outlet of reflow hole and the pressure of the cool circulation channel become smaller. The pressure of cooling channel gradually decreases in flow process from deflector hole to reflow hole, and the area of low pressure is easily formed near the outlet of reflow hole.

In order to study the effect of geometrical parameters of magnetic drive coupling on magnetic torque and magnetic eddy current loss, based on the basic theory of electromagnetic field, the influence factors of magnetic performance of combined push-pull magnetic drive coupling are analyzed and optimized by means of finite element numerical calculation and orthogonal experiment. The optimal geometrical parameter scheme of magnetic drive coupling was obtained, and the magnetic performance of the optimal geometrical parameter model was studied experimentally. The geometrical parameters of the optimal scheme of magnetic drive coupling are internal radius of magnet r = 80 mm, thickness of permanent magnet tm = 8 mm, axial length Lb = 144 mm, and thickness of yoke iron ti = 10 mm. The research shows that the optimization design method proposed in this paper is reliable in the design of magnetic drive coupling and can provide some theoretical reference for the design of magnetic drive coupling and the optimization of magnetic torque and magnetic eddy current loss.

In order to reveal the evolution law of heat transfer during phase change in a corrugated plate flow passage of a plate heat exchanger, a two-dimensional two-channel model was established to simulate the process of heat transfer during phase change in an unsteady flow passage. The results show that when the time was &lt, 3/5T, the average Nusselt number and average heat flux of the heat exchange wall surface decreased with time, the average temperature of the cold fluid outlet increased, the average temperature of the hot fluid outlet decreased, and the volume fraction of the gas phase was no higher than 0.2. When the time was &gt, 3/5T, the average Nusselt number and the average heat flux of the heat exchange wall, as well as the outlet average temperature of the cold and hot fluid, reached stability, while the volume fraction of the gas phase increased rapidly. During the whole heat transfer process, the change in Nusselt number and heat flux along the heat transfer wall surface was basically the same, and its value fluctuated along the wall surface, displaying extrema at the exit, entrance, and corrugated corner. The temperature of the heat exchange wall fluctuated and increased along the Y-axis, and began stabilizing after a time &gt, 3/5T. As time went on, the temperature gradient of the hot and cold fluid outlet and the temperature difference between the two sides of the heat exchange wall decreased, whereas the relative parameters of the heat flow inlet section of the corrugated passage reached stability before those of the cold flow inlet section. The whole simulation process fully reflects the heat transfer mechanism during phase change in a corrugated plate flow passage of a plate heat exchanger.