Is the Bernoulli's equation for airplane wings using metric units correct?

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    Bernoulli's Law
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SUMMARY

The Bernoulli equation can be applied to airplane wings using metric units, specifically the expression for dynamic pressure: Difference in pressure = 1/2 x air density x [(airflow velocity below wing)^2 - (airflow velocity above wing)^2]. The units correctly align when using kg/m³ for density and m/s for velocity, resulting in N/m², which is consistent with pressure measurements. The discussion confirms that the equation assumes no friction, no potential energy changes, and no compressibility effects, validating its application in aerodynamics.

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Hi everyone,

I read on a website that the Bernoulli's expression can be applied to airplane wings by using the equation:

Difference in pressure above and below wing
= 1/2 x air density x [(airflow velocity below wing)^2 - (airflow velocity above wing)^2]


I tried using it but the units don't seem to add up correctly when I use the metric system (kg/m^3 for density, m/s for velocity).
The website uses (slugs/ft^3) for density, and (ft/s) for velocity.

Can anybody tell me if this equation is correct?
 
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What they express is simply the difference in dynamic pressure. Dynamic pressure is the first term in the Bernoulli equation. This makes the assumptions that there is no friction, no potential energy change and no compressibility effects.

Since it is dynamic pressure, the units do work out.

\frac{1}{2}\rho V^2

\frac{kg}{m^3}\frac{m^2}{s^2}

\frac{kg*m^2}{m^3*s^2}

\frac{kg*m}{s^2}\frac{m}{m^3}

\frac{N}{m^2}
 

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