AnsweredAssumed Answered

Pump simulation

Question asked by Manuel Perarnau on May 3, 2015
Latest reply on May 9, 2015 by Manuel Perarnau

Hello Solidworks forum,

 

I have used solidworks many times before to do sketches and blueprints, but this is the first time I have use it to simulate flows.

 

Overview:

I'm trying to evaluate the performance of a custom pump that manages a very dense and viscous fluid through a rather small piping system.

 

System:

Assuming a flow required and a small reservoir to hold the fluid, I calculated the head needed from the pump. The pump itself is basically a horizontally placed Archimedes screw inside a cylinder.

 

Modeling:

Once the screw was sketched, assuming a certain length and number of coils, the pump was assembled. According to the tutorials, a solid cylinder was created concentric to the screw to simulate the rotating region, but made invisible in the "Component control" option.

Later, according to the calculations made earlier, I set an inlet and outlet pressure. The inlet pressure was the pressure produced by the column of fluid in the reservoir, while the outlet was set to be the pressure that the pump has to overcome.

The system is such that the pump needs to create 73421 Pa of gauge pressure on the outlet, while having a tank on the inlet that translates to 1234 Pa of gauge pressure.

 

Simulation:

After several simulations using a mesh in the third setting, I got the following results using different boundary conditions:

 

Inlet

[Pa]

Outlet

[Pa]

Fluid

[m3/s]

Type

Pressure

Type

Pressure

Direction

Flow

Static

1234

Static

73421

Backwards

3,80E-04

Environment

101325

Static

73421

Correct

1,60E-04

Environment

101325

Static

174746

Backwards

3,86E-04

 

It appears that  the pump isn't really doing anything (it rotates at 30RPM), because the flow just goes from high to low pressure, but I am still not convinced that the boundary conditions are set correctly. Given that the fluid is glycerin (the closest thing to the actual fluid I'm using) I assumed that the viscosity would help  "adhere" to the slow rotating impeller and carry it to the end of the pump where it would encounter a sudden rise in pressure.

 

Are the conditions set properly or is the pump itself that isn't creating any pressure?Flow lines 1.jpgFlow lines 2.jpg

Basic layout.jpg

Thank you for your patience and help.

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