Torque Converter Pump Torque = Engine Torque?

Torque_Converter · November 8, 2012, 15:26

This seems like the silliest thing to be caught up in, but I keep seeing correct Turbine output torques, but the Pump torque from analysis puts out higher values than Engine input torque. It would seem this is impossible by conservation of energy, but the torque production in the Turbine is always so right at every SR, even in other Torque Converters.

Is it possible the pump reaction torque from spinning at a given RPM is different from the engine input torque?

husker · November 9, 2012, 02:16

Can you please give more details?

Torque_Converter · November 9, 2012, 09:12

The pump is connected directly to the engine. But when I simulate it moving at the same speed in CFX it produces a different torque than the engine. Should it produce the same torque due to conservation of energy, or a different torque because CFX is calculating "reaction" torque which is different?

husker · November 12, 2012, 03:30

Please let me explain what I understand.

You are simulating the flow inside a pump and the resultant torque value is higher than the test value. Is this true?

If so, there may be many reasons involving the over-estimation of the torque. Such as working conditions of the pump, the physical assumptions and the flow differences between the test and the simulation.

Can you please share a diagram or a screenshot of your problem? Also the details of the physical setup, boundary conditions and the mesh.

Regards

Torque_Converter · November 12, 2012, 07:44

I'm sorry, I'm still not explaining it right.

The engine is turning a pump at a certain RPM with a certain engine torque.

However, there is a torque calculated inside the pump in CFX based on the reaction of the fluid. The absolute value of this torque is higher, and the direction is the opposite of the engine.

I believe the two should be different due to blade differences, wall shear, and the fluid not always moving circumferentially the same speed as the solid of the walls blades. I.e. speed ratio effect.

November 8, 2012, 15:26	Torque Converter Pump Torque = Engine Torque?	#1
Torque_Converter Member Join Date: Jan 2012 Location: Edmonton, CA Posts: 87 Rep Power: 14	This seems like the silliest thing to be caught up in, but I keep seeing correct Turbine output torques, but the Pump torque from analysis puts out higher values than Engine input torque. It would seem this is impossible by conservation of energy, but the torque production in the Turbine is always so right at every SR, even in other Torque Converters. Is it possible the pump reaction torque from spinning at a given RPM is different from the engine input torque?

November 12, 2012, 03:30		#4
husker Member Join Date: Mar 2009 Posts: 85 Rep Power: 17	Please let me explain what I understand. You are simulating the flow inside a pump and the resultant torque value is higher than the test value. Is this true? If so, there may be many reasons involving the over-estimation of the torque. Such as working conditions of the pump, the physical assumptions and the flow differences between the test and the simulation. Can you please share a diagram or a screenshot of your problem? Also the details of the physical setup, boundary conditions and the mesh. Regards Last edited by husker; November 12, 2012 at 08:32.

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November 9, 2012, 02:16		#2
husker Member Join Date: Mar 2009 Posts: 85 Rep Power: 17	Can you please give more details?

November 9, 2012, 09:12		#3
Torque_Converter Member Join Date: Jan 2012 Location: Edmonton, CA Posts: 87 Rep Power: 14	The pump is connected directly to the engine. But when I simulate it moving at the same speed in CFX it produces a different torque than the engine. Should it produce the same torque due to conservation of energy, or a different torque because CFX is calculating "reaction" torque which is different?

November 12, 2012, 07:44		#5
Torque_Converter Member Join Date: Jan 2012 Location: Edmonton, CA Posts: 87 Rep Power: 14	I'm sorry, I'm still not explaining it right. The engine is turning a pump at a certain RPM with a certain engine torque. However, there is a torque calculated inside the pump in CFX based on the reaction of the fluid. The absolute value of this torque is higher, and the direction is the opposite of the engine. I believe the two should be different due to blade differences, wall shear, and the fluid not always moving circumferentially the same speed as the solid of the walls blades. I.e. speed ratio effect.