Xiaobai asks for help on the principle of reducing the suction pressure of a centrifugal pump when the pump is turned on
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Please tell me: After the system is filled with water and the circulating water pump is started, why does the value of the suction pressure gauge drop? Some colleagues used Bernoulli's equation to explain to me: Since the pressure gauge measures static pressure, the fluid has a flow rate after the pump is turned on, the dynamic pressure increases, and the static pressure decreases. But what I don’t understand is that the static pressure at the outlet of the water pump has increased. This cannot be explained using Bernoulli’s equation. Please give me some advice.
It is completely explained that the outlet static pressure increases because the pump does work on the liquid.
Can't work be explained by Bernoulli's equation?
The inlet and outlet energy are not conserved because the energy increases as the pump does its work.
When the centrifugal pump is running, the center of the impeller has a negative pressure relative to the outside of the impeller.
I don’t really understand it, but I think it shouldn’t have any impact.
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After the pump is turned on, the fluid has a flow rate, the dynamic pressure increases, and the static pressure decreases. This explanation is correct.
I still don’t understand what everyone said above. Can you explain in detail the changing process of static pressure and dynamic pressure in the inlet and outlet pipelines?
The water pump outlet also has a flow rate, so why does the dynamic pressure increase and the static pressure also increase? That's what makes me confused
Does that mean it can't be explained by Bernoulli's equation? So how should we understand the changing process of system static pressure and dynamic pressure during the process of starting and stopping the pump?