Page 8 - FANS. Aerodynamic _Selection Meethod__Combine_part2

6-7 is the total pressure of the fan in the absence of a ventilation network,
equal to the calculated value of the dynamic pressure in the absence of a
ventilation network, Рt6 = Рv6.

If you set the parameters of the ventilation network Pt9 and L9, then the
fan will set the “working point” of the ventilation system in vol.

At one time, a mistake was made which fixed the artificial separation of the
total pressure of the fan to the static pressure of the fan Ps and the dynamic
pressure of the fan Pv (on the discharge pipe of the fan).

That part of the total pressure, which was called the static pressure of the
fan, introduced and mislead engineers and periodically different opinions
arise - how to conduct calculations? how to pick up a fan? “By complete” or
“by static” - in certain cases.

It is believed that the static pressure of the fan reflects the magnitude of the

pressure drop in the ventilation network (with some reservations), but its
meaning is not completely clear. Moreover, the static pressure of the fan is
taken as the sum of the total pressure at the suction nozzle and the static
pressure at the discharge nozzle.

Note: The terms 'full', 'static', 'dynamic' to evaluate

ratios of these pressures and determine the air velocity in

duct not questioned are present in

Bernoulli equations and relate to the movement of air

in the duct and do not need any explanations.

These terms can be operated on while driving

air flow in the atmosphere. Arbitrarily these terms

were transferred to the aerodynamic characteristics

fan that played a negative role.