Block used to send speed signal

Bhuvana Siva Teja

Hi,

I am working on hydraulics and stuck with a bit of confusion. We give speed input to the pump using "ConstantSpeed block". But the problem is, my speed is dynamic, coming from engine curve depending on the torque of each pump. I am able to take torque from the pumps and get respective speed from the engine curve. But the value of speed is just a constant which pump cannot understand it is the RPM, unless i feed a constantspeed block.  Is there any way that the speed value coming from the engine curve can be fed to pump so that, pump understand it as speed input?

Spiros-Foivos Mallios_22475

Bhuvana Siva Teja said:

Hi Spiros,

Thank you for the information, But the input we get from Engine is RPM. So, using a torque block will give the input speed as a troque right? I want a block which takes constant as input and give speed signal as output to the pump.

Hi Bhuvana,

In this case you can use the "Speed" block from the Modelica Modelica/Mechanics/Rotational/Sources library. This is demonstrated in "Pump test.csm" demo model.

This "Speed" block takes as an input a signal (can be from a constant block , ramp, look up table , etc.) and converts it into angular velocity in rad/s.

Link to block info:  Speed (altair.com)

 

Please let us know if you have any more questions,

Thanks

Spiros

Spiros-Foivos Mallios_22475

Hi Bhuvana

You can directly impose the Torque coming from the engine on the pump instead of the velocity.

To do this you need to use the  "Torque" modellica source block as shown bellow

Here is a practical example , i modified the "Pump test.scm" model from the Demo Browser and swapped the Speed block with the Torque block. Now the input is the torque values which in this case is a ramp-saturate curve. In your case the torque signal would come from the engine.

Hope its clear

Let us know if you any more questions

Kind Regards

Spiros

Bhuvana Siva Teja

Spiros-Foivos Mallios_22475 said:

Hi Bhuvana

You can directly impose the Torque coming from the engine on the pump instead of the velocity.

To do this you need to use the  "Torque" modellica source block as shown bellow

Here is a practical example , i modified the "Pump test.scm" model from the Demo Browser and swapped the Speed block with the Torque block. Now the input is the torque values which in this case is a ramp-saturate curve. In your case the torque signal would come from the engine.

Hope its clear

Let us know if you any more questions

Kind Regards

Spiros

Hi Spiros,

Thank you for the information, But the input we get from Engine is RPM. So, using a torque block will give the input speed as a troque right? I want a block which takes constant as input and give speed signal as output to the pump.

Spiros-Foivos Mallios_22475

Bhuvana Siva Teja said:

Hi Spiros,

Thank you for the information, But the input we get from Engine is RPM. So, using a torque block will give the input speed as a troque right? I want a block which takes constant as input and give speed signal as output to the pump.

Hi Bhuvana,

In this case you can use the "Speed" block from the Modelica Modelica/Mechanics/Rotational/Sources library. This is demonstrated in "Pump test.csm" demo model.

This "Speed" block takes as an input a signal (can be from a constant block , ramp, look up table , etc.) and converts it into angular velocity in rad/s.

Link to block info:  Speed (altair.com)

 

Please let us know if you have any more questions,

Thanks

Spiros

Bhuvana Siva Teja

Spiros-Foivos Mallios_22475 said:

Hi Bhuvana,

In this case you can use the "Speed" block from the Modelica Modelica/Mechanics/Rotational/Sources library. This is demonstrated in "Pump test.csm" demo model.

This "Speed" block takes as an input a signal (can be from a constant block , ramp, look up table , etc.) and converts it into angular velocity in rad/s.

Link to block info:  Speed (altair.com)

 

Please let us know if you have any more questions,

Thanks

Spiros

Hi Spiros,

Awesome, Its working. Thank you so much.