Hydraulic Gas-Charged Accumulator

I am trying to implement a system where a gas-charged accumulator is used to smooth out the flow from a rotary actuator pump. However I am finding that no what I do the accumulator never fills with any fluid. Even if I set the pre-charge pressure to just above 0 the accumulator will still not fill.

*Note: There is a pressure differential large enough that at times the accumulator should have filled

Answer 1

[Guy Rouleau]

The only thing I can guess based on your description is that you have something connected wrong.

Did you look at the demo "sh_accumulator_gas_circuit.mdl"?

I would start with this demo and try figuring out what is different in your model.

If you make your model available or provide more details on how it is connected, it should be possible to give a better explanation.

[Andrew]

As far as I can tell it is hooked up correctly, there is only one line so I can't think of how it could be hooked up incorrectly. The only thing between the accumulator and the main circuit is a flow sensor block.

This is my model, http://dl.dropbox.com/u/2510110/HydroModle.mdl

[Guy Rouleau]

I agree... the gas-charged accumulator look connected correctly. However you did not provide the variables to run the model.

I am not sure, but I feel like the 2 flow sensors might short-circuit the pumps... I would need to be able to run the model to figure something else.

[Andrew]

Guy,

Here is the constants file, http://dl.dropbox.com/u/2510110/Constants.m

I ran my model again and removed all the flow sensors before the accumulator except for the one which will tell me if there is flow into the accumulator. Nothing changed. I looked over the demo model in more detail, the biggest differences I see are they are using a pressure source and I'm using a flow source. They also have an "open" system vs my "closed" system.

Thanks for your help

-Andrew