Formulae Used - Etesia HYDRO 124D Technical Training Manual

4) Application to the Hydro 124D

4.1) Formulae used.

FLOW
FLOW = (CUBIC CAPACITY OF PUMP x ROTATIONAL SPEED OF PUMP) / 1000
The flow is expressed in litres/minute (l/min)
The cubic capacity is expressed in cubic centimetres / revolution (cm3/rev)
The rotational speed is expressed in revolutions per minute (rpm)
ROTATIONAL SPEED
ROTATIONAL SPEED = (1000 x FLOW) / CUBIC CAPACITY.
POWER
POWER = (FLOW x PRESSURE) / 600
The power is expressed in kW (1kW=1000 Watts)
The flow is expressed in litres/minute (l/min)
The pressure in bars
This formula can also allow the calculation of a pressure according to a power and a flow. It is presented in the following form :
PRESSURE = (600 x POWER) / FLOW
TORQUE
TORQUE = (950 x POWER) / ROTATIONAL SPEED
The couple is expressed in daN.m (deca-Newton x metre) (1 daN= 10 Newtons)
The power is expressed in kW
The rotational speed is expressed in rpm
NB : if we look more closely, we see that flow, power and torque are connected. This is to say that by
acting on or modifying one value (for example the rotational speed of a pump), all the other values
change, but not necessarily for the better.
We will see later on that the consequences of the modification (increase) in the rate of the diesel engine
may be.
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