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I am trying to estimate and validate the pressure of water exiting a nozzle. For an unknown reason, the validation is consistently twice as high as the estimation.

Here the approach:

I am using the dynamic pressure equation for the estimation:

q = 1/2 * ρ * u

where,

q = dynamic pressure

ρ = density of water (997 kg/m

u = liquid velocity

The velocity is calculated based on the known nozzle diameter and the flow rate (u = flow rate / nozzle area)

The measurement is performed by simply measuring the jet force with a force gauge in horizontal orientation and in short distance (<1cm) - see the schematic. The assumption is that the jet diameter is the same as the nozzle.

q_val = jet force / nozzle area.

As mentioned before, in varying measurements the validation is close to being twice of the estimation data.

Is there anything I'm missing here?

I am trying to estimate and validate the pressure of water exiting a nozzle. For an unknown reason, the validation is consistently twice as high as the estimation.

Here the approach:

__Estimation:__I am using the dynamic pressure equation for the estimation:

q = 1/2 * ρ * u

^{2}where,

q = dynamic pressure

ρ = density of water (997 kg/m

^{3})u = liquid velocity

The velocity is calculated based on the known nozzle diameter and the flow rate (u = flow rate / nozzle area)

__Validation:__The measurement is performed by simply measuring the jet force with a force gauge in horizontal orientation and in short distance (<1cm) - see the schematic. The assumption is that the jet diameter is the same as the nozzle.

q_val = jet force / nozzle area.

As mentioned before, in varying measurements the validation is close to being twice of the estimation data.

Is there anything I'm missing here?