Applying the momentum equation to the control volume of a convergent nozzle for inviscid, incompressible, low speed flow, the thrust is(adsbygoogle = window.adsbygoogle || []).push({});

[tex]mV_{entry} - mV_{exit} + (P_{exit} - P_{ambient})A_{exit}[/tex]

where

[tex]m=A_{entry}*V_{entry}[/tex]mass flow per unit time

[tex]V_{entry}=[/tex]entry velocity from the front of the nozzle.

[tex]V_{exit}=[/tex]exit velocity of the nozzle air.

[tex]P_{exit}=[/tex]static pressure at exit

[tex]P_{ambient}[/tex]Ambient static pressure

[tex]A_{exit}=[/tex]exit area

For mass flow 4 mg, entry velocity 1 m/s, entry area 4 mm2, exit area 1mm2, exit velocity 4 m/s, the difference between exit and ambient static pressure is -9.225 Pa.

Thrust comes to 2.775E-6. Small but still there is thrust. Is it possible assuming the ideal conditions mentioned above?

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