Pressure drop in a large industrial motor

[buggles]

Hi,

I'm trying to work out the pressure drop in a 4778kW, 4kV, 60Hz, industrial motor.

The airflow/cooling air is generated by the motor through the vent spacers.

There are 8 inlet air vents of 135000mm^2 each with a minimum steel mesh area of 45% on each mesh. 4 at each side of the motor, the outlet air vents are sandwiched between the the air inlets at either side, therefore there are 4 oulet air vents.

Outlet air vents are 718900mm^2.

Total air quantity for the motor is 5.189E9mm^3/s;
the velocity of air through the inlet ducts is 9.563E4mm^2/s;
the velocity of air through the outlet ducts is 8.081E3mm^2/s

Could anyone help me with regards to calculations involved in this analysis?

 

[gerhardl]

Is this to optimize the construction of the cooling flow 'lead' through the motor or what?

In my opinion it would be better to find a way to measure the pressure at both ends, the pressure loss would be guessed to be so low that any approximating calculation would be unsure or give a too wide variation.

The temperature diference entering and going out would be essential to know anyway as part of the calculation. (May (p1 x v1)/T1 =(p2 x v2)/T2 be used? p2 + delta p = p1. Anyone?)

 

[WoodyPE]

Is the motor running too hot? Are you designing a motor or are you the end user? What are the issues?